diff --git a/pl/absf.yap b/pl/absf.yap
index dccdcda57..d535e03c9 100755
--- a/pl/absf.yap
+++ b/pl/absf.yap
@@ -377,7 +377,7 @@ absolute_file_name(File0,File) :-
 	'$system_catch'(win_registry_get_value(HKEY, Library, Dir), prolog,_,fail).
 % not installed on registry
 '$system_library_directories'(Library, Dir) :-
-	'$yap_paths'(_DLLs, ODir1, OBinDir ),
+	'$yap_paths'(_DLLs, ODir1, _OBinDir ),
 %	'$absolute_file_name'( OBinDir, BinDir ),
 %	'$swi_current_prolog_flag'(executable, Bin1),
 %	prolog_to_os_filename( Bin2, Bin1 ),
@@ -434,7 +434,7 @@ absolute_file_name(File0,File) :-
     '$split_by_sep'(Start, N1, Dirs, Sep, Dir).
 
 
-'$extend_path_directory'(_Name, D, File, _Opts, File, Call) :-
+'$extend_path_directory'(_Name, _D, File, _Opts, File, _Call) :-
 	is_absolute_file_name(File), !.
 '$extend_path_directory'(Name, D, File, Opts, NewFile, Call) :-
 	user:file_search_path(Name, IDirs),
@@ -472,7 +472,7 @@ prolog_file_name(File, PrologFileName) :-
 	atom(File), !,
 	operating_system_support:true_file_name(File, PrologFileName).
 prolog_file_name(File, PrologFileName) :-
-	'$do_error'(type_error(atom,T), prolog_file_name(File, PrologFileName)).
+	'$do_error'(type_error(atom,File), prolog_file_name(File, PrologFileName)).
 
 /**
   @pred path(-Directories:list) is det,deprecated
diff --git a/pl/arith.yap b/pl/arith.yap
index 43daba466..8e0aec8c5 100644
--- a/pl/arith.yap
+++ b/pl/arith.yap
@@ -189,6 +189,31 @@ do_c_built_in(X is Y, _, P) :-
 		expand_expr(Y, P0, X0),
 		'$drop_is'(X0, X, P0, P)
 	).
+do_c_built_in(phrase(NT,Xs), Mod, NTXsNil) :-
+	'$_arith':do_c_built_in(phrase(NT,Xs,[]), Mod, NTXsNil).
+do_c_built_in(phrase(NT,Xs0,Xs), Mod, NewGoal) :-
+    '$goal_expansion_allowed'(phrase(NT,Xs0,Xs), Mod),
+    Goal = phrase(NT,Xs0,Xs),
+    callable(NT),
+    catch('$translate_rule'((pseudo_nt --> NT), Rule),
+	  error(Pat,ImplDep),
+	  ( \+ '$harmless_dcgexception'(Pat), 
+	    throw(error(Pat,ImplDep))
+	  )
+	 ),
+    Rule = (pseudo_nt(Xs0c,Xsc) :- NewGoal0),
+    Goal \== NewGoal0,
+    % apply translation only if we are safe
+    \+ '$contains_illegal_dcgnt'(NT), !,
+    (   var(Xsc), Xsc \== Xs0c
+	->  Xs = Xsc, NewGoal1 = NewGoal0
+	;   NewGoal1 = (NewGoal0, Xsc = Xs)
+    ),
+    (   var(Xs0c)
+	-> Xs0 = Xs0c,
+	   NewGoal = NewGoal1
+	;  ( Xs0 = Xs0c, NewGoal1 ) = NewGoal
+    ).
 do_c_built_in(Comp0, _, R) :-		% now, do it for comparisons
 	'$compop'(Comp0, Op, E, F),
 	!,
@@ -197,32 +222,7 @@ do_c_built_in(Comp0, _, R) :-		% now, do it for comparisons
 	expand_expr(F, Q, V),
 	'$do_and'(P, Q, R0),
 	'$do_and'(R0, Comp, R).
-do_c_built_in(phrase(NT,Xs), NTXsNil) :-
-	'$_arith':do_c_built_in(phrase(NT,Xs,[]), NTXsNil).
-
-do_c_built_in(phrase(NT,Xs0,Xs), Mod, NewGoal) :-
-	'$goal_expansion_allowed'(phrase(NT,Xs0,Xs), Mod),
-	Goal = phrase(NT,Xs0,Xs),
-	callable(NT),
-	catch('$translate_rule'((pseudo_nt --> NT), Rule),
-	      error(Pat,ImplDep),
-	      ( \+ '$harmless_dcgexception'(Pat), 
-		throw(error(Pat,ImplDep))
-	      )),
-	Rule = (pseudo_nt(Xs0c,Xsc) :- NewGoal0),
-	Goal \== NewGoal0,
-	% apply translation only if we are safe
-	\+ '$contains_illegal_dcgnt'(NT), !,
-	(   var(Xsc), Xsc \== Xs0c
-	->  Xs = Xsc, NewGoal1 = NewGoal0
-	;   NewGoal1 = (NewGoal0, Xsc = Xs)
-	),
-	(   var(Xs0c)
-	-> Xs0 = Xs0c,
-	   NewGoal = NewGoal1
-	;  ( Xs0 = Xs0c, NewGoal1 ) = NewGoal
-	).
-do_c_built_in(P, _, P).
+do_c_built_in(P, _M, P).
 
 do_c_built_metacall(G1, Mod, '$execute_wo_mod'(G1,Mod)) :- 
 	var(Mod), !.
@@ -241,11 +241,13 @@ do_c_built_metacall(G1, Mod, call(Mod:G1)).
 % V is the result of the simplification,
 % X the result of the initial expression
 % and the last argument is how we are writing this result
-'$drop_is'(V, V1, P0, G) :- var(V), !,		% usual case
-        V = V1, P0 = G.
+'$drop_is'(V, V1, P0, G) :- 
+    var(V),
+    !,		% usual case
+    V = V1,
+    P0 = G.
 '$drop_is'(V, X, P0, P) :-			% atoms
-        '$do_and'(P1, X is V, P).
-
+    '$do_and'(P0, X is V, P).
 
 % Table of arithmetic comparisons
 '$compop'(X < Y, < , X, Y).
@@ -394,32 +396,6 @@ expand_expr(Op, X, Y, O, Q, P) :-
 	'$do_and'(Z = X, Y = W, E).
 
 
-do_c_built_in(phrase(NT,Xs), NTXsNil) :-
-	'$_arith':do_c_built_in(phrase(NT,Xs,[]), NTXsNil).
-
-do_c_built_in(phrase(NT,Xs0,Xs), Mod, NewGoal) :-
-	'$goal_expansion_allowed'(phrase(NT,Xs0,Xs), Mod),
-	Goal = phrase(NT,Xs0,Xs),
-	callable(NT),
-	catch('$translate_rule'((pseudo_nt --> NT), Rule),
-	      error(Pat,ImplDep),
-	      ( \+ '$harmless_dcgexception'(Pat), 
-		throw(error(Pat,ImplDep))
-	      )),
-	Rule = (pseudo_nt(Xs0c,Xsc) :- NewGoal0),
-	Goal \== NewGoal0,
-	% apply translation only if we are safe
-	\+ '$contains_illegal_dcgnt'(NT), !,
-	(   var(Xsc), Xsc \== Xs0c
-	->  Xs = Xsc, NewGoal1 = NewGoal0
-	;   NewGoal1 = (NewGoal0, Xsc = Xs)
-	),
-	(   var(Xs0c)
-	-> Xs0 = Xs0c,
-	   NewGoal = NewGoal1
-	;  ( Xs0 = Xs0c, NewGoal1 ) = NewGoal
-	).
-
 '$goal_expansion_allowed'(phrase(_NT,_Xs0,_Xs), _Mod).
 
 %%	contains_illegal_dcgnt(+Term) is semidet.
diff --git a/pl/atoms.yap b/pl/atoms.yap
index 6577c345d..ef8ce709e 100644
--- a/pl/atoms.yap
+++ b/pl/atoms.yap
@@ -45,21 +45,21 @@ atom_concat(Xs,At) :-
 % just slice first atom
 '$atom_concat_constraints'([At0|Xs], 0, At, Unbound) :-
 	atom(At0), !,
-	sub_atom(At, 0, Sz, L, At0 ),
+	sub_atom(At, 0, _Sz, L, At0 ),
 	sub_atom(At, _, L, 0, Atr ), %remainder
 	'$atom_concat_constraints'(Xs, 0, Atr, Unbound).
 % first hole: Follow says whether we have two holes in a row, At1 will be our atom
 '$atom_concat_constraints'([At0|Xs], 0, At, [hole(At0, 0, At, Next)|Unbound]) :-
-	 '$atom_concat_constraints'(Xs, mid(Next,At1), At, Unbound).
+	 '$atom_concat_constraints'(Xs, mid(Next,_At1), At, Unbound).
 % end of a run
 '$atom_concat_constraints'([At0|Xs], mid(end, At1), At, Unbound) :-
 	atom(At0), !,
-	sub_atom(At, Next, Sz, L, At0),
+	sub_atom(At, Next, _Sz, L, At0),
 	sub_atom(At, 0, Next, Next, At1),
 	sub_atom(At, _, L, 0, Atr), %remainder
 	'$atom_concat_constraints'(Xs, 0, Atr, Unbound).
 '$atom_concat_constraints'([At0|Xs], mid(Next,At1), At, Next, [hole(At0, Next, At, Follow)|Unbound]) :-
-	 '$atom_concat_constraints'(Xs, mid(NextFollow, At1), At, Unbound).
+	 '$atom_concat_constraints'(Xs, mid(Follow, At1), At, Unbound).
 
 '$process_atom_holes'([]).
 '$process_atom_holes'([hole(At0, Next, At1, End)|Unbound]) :- End == end, !,
@@ -190,21 +190,21 @@ string_concat(Xs,At) :-
 % just slice first string
 '$string_concat_constraints'([At0|Xs], 0, At, Unbound) :-
 	string(At0), !,
-	sub_string(At, 0, Sz, L, At0 ),
+	sub_string(At, 0, _Sz, L, At0 ),
 	sub_string(At, _, L, 0, Atr ), %remainder
 	'$string_concat_constraints'(Xs, 0, Atr, Unbound).
 % first hole: Follow says whether we have two holes in a row, At1 will be our string
 '$string_concat_constraints'([At0|Xs], 0, At, [hole(At0, 0, At, Next)|Unbound]) :-
-	 '$string_concat_constraints'(Xs, mid(Next,At1), At, Unbound).
+	 '$string_concat_constraints'(Xs, mid(Next,_At1), At, Unbound).
 % end of a run
 '$string_concat_constraints'([At0|Xs], mid(end, At1), At, Unbound) :-
 	string(At0), !,
-	sub_string(At, Next, Sz, L, At0),
+	sub_string(At, Next, _Sz, L, At0),
 	sub_string(At, 0, Next, Next, At1),
 	sub_string(At, _, L, 0, Atr), %remainder
 	'$string_concat_constraints'(Xs, 0, Atr, Unbound).
 '$string_concat_constraints'([At0|Xs], mid(Next,At1), At, Next, [hole(At0, Next, At, Follow)|Unbound]) :-
-	 '$string_concat_constraints'(Xs, mid(NextFollow, At1), At, Unbound).
+	 '$string_concat_constraints'(Xs, mid(Follow, At1), At, Unbound).
 
 '$process_string_holes'([]).
 '$process_string_holes'([hole(At0, Next, At1, End)|Unbound]) :- End == end, !,
diff --git a/pl/checker.yap b/pl/checker.yap
index 72e299c6e..4d64d938f 100644
--- a/pl/checker.yap
+++ b/pl/checker.yap
@@ -129,7 +129,7 @@ style_check(V) :-
 	'$do_error'( type_error('+|-|?(Flag)', V), style_check(V) ).
 style_check(V) :-
 	\+atom(V), \+ list(V), V \= + _, V \= + _, !,
-	'$do_error'( domain_error(style_name(Flag), V), style_check(V) ).
+	'$do_error'( domain_error(style_name, V), style_check(V) ).
 	
 
 style_check_(all) :-
@@ -183,7 +183,7 @@ style_check_(+charset) :-
 style_check_(-charset) :-
 	'$style_checker'( [  -charset ] ).
 style_check_('?'(Info) ) :-
-	lists:member( Style,  [ singleton, discontiguous, multiple ] ),
+	L =  [ singleton, discontiguous, multiple ],
 	( lists:member(Style, L ) -> Info = +Style ; Info = -Style ).
 style_check_([]).
 style_check_([H|T]) :- style_check(H), style_check(T).
diff --git a/pl/consult.yap b/pl/consult.yap
index 0a87209b5..245940d43 100644
--- a/pl/consult.yap
+++ b/pl/consult.yap
@@ -234,13 +234,18 @@ load_files(Files,Opts) :-
 '$lf_option'('$context_module', 27, _).
 '$lf_option'('$parent_topts', 28, _).
 '$lf_option'(must_be_module, 29, false).
+'$lf_option'('$source_pos', 30, _).
 
-'$lf_option'(last_opt, 29).
+'$lf_option'(last_opt, 30).
 
 '$lf_opt'( Op, TOpts, Val) :-
 	'$lf_option'(Op, Id, _),
 	arg( Id, TOpts, Val ).
 
+'$set_lf_opt'( Op, TOpts, Val) :-
+	'$lf_option'(Op, Id, _),
+	setarg( Id, TOpts, Val ).
+
 '$load_files'(Files, Opts, Call) :-
 	( '$nb_getval'('$lf_status', OldTOpts, fail), nonvar(OldTOpts) ->
 	  '$lf_opt'(silent, OldTOpts, OldVerbosity),
@@ -374,8 +379,8 @@ load_files(Files,Opts) :-
 	( Val == false -> true ;
 	    Val == true -> true ;
 	    '$do_error'(domain_error(unimplemented_option,register(Val)),Call) ).
-'$process_lf_opt'('$context_module', Val, Call) :-
-	( atom(File) -> true ;  '$do_error'(type_error(atom,File),Call) ).
+'$process_lf_opt'('$context_module', Mod, Call) :-
+	( atom(Mod) -> true ;  '$do_error'(type_error(atom,Mod),Call) ).
 
 
 '$lf_default_opts'(I, LastOpt, _TOpts) :- I > LastOpt, !.
@@ -417,7 +422,7 @@ load_files(Files,Opts) :-
 '$lf'(user_input, Mod, _, TOpts) :- !,
 	b_setval('$source_file', user_input),
 	'$do_lf'(Mod, user_input, user_input, TOpts).
-'$lf'(File, Mod, Call, TOpts) :-
+'$lf'(File, Mod, _Call, TOpts) :-
     '$lf_opt'(stream, TOpts, Stream),
     var( Stream ),
     H0 is heapused, '$cputime'(T0,_),
@@ -463,6 +468,7 @@ load_files(Files,Opts) :-
     '$lf_opt'(imports, TOpts, Imports),
     '$start_lf'(If, Mod, Stream, TOpts, File, Reexport, Imports),
     character_count(Stream, Pos),
+    '$set_lf_opt'('$source_pos', TOpts, Pos),
     close(Stream). 
 '$lf'(X, _, Call, _) :-
     '$do_error'(permission_error(input,stream,X),Call).
@@ -471,15 +477,15 @@ load_files(Files,Opts) :-
 	'$file_loaded'(Stream, Mod, Imports, TOpts), !,
 	'$lf_opt'('$options', TOpts, Opts),
 	'$lf_opt'('$location', TOpts, ParentF:Line),
-	'$loaded'(Stream, UserFile, Mod, ParentF, Line, not_loaded, _File, _Dir, Opts),
+	'$loaded'(Stream, UserFile, Mod, ParentF, Line, not_loaded, _, _File, _Dir, Opts),
 	'$reexport'( TOpts, ParentF, Reexport, Imports, _File ).
 '$start_lf'(changed, Mod, Stream, TOpts, UserFile, Reexport, Imports) :-
 	'$file_unchanged'(Stream, Mod, Imports, TOpts), !,
 	'$lf_opt'('$options', TOpts, Opts),
 	'$lf_opt'('$location', TOpts, ParentF:Line),
-	'$loaded'(Stream, UserFile, Mod, ParentF, Line, changed, _File, _Dir, Opts),
+	'$loaded'(Stream, UserFile, Mod, ParentF, Line, changed, _, _File, _Dir, Opts),
 	'$reexport'( TOpts, ParentF, Reexport, Imports, _File ).
-'$start_lf'(_, Mod, Stream, TOpts, File, Reexport, Imports) :-
+'$start_lf'(_, Mod, Stream, TOpts, File, _Reexport, _Imports) :-
 	'$do_lf'(Mod, Stream, File, TOpts).
 
 
@@ -654,7 +660,7 @@ db_files(Fs) :-
 	'$lf_opt'(consult, TOpts, Reconsult0),
 	'$lf_opt'('$options', TOpts, Opts),
 	'$lf_opt'('$location', TOpts, ParentF:Line),
-	'$loaded'(Stream, UserFile, SourceModule, ParentF, Line, Reconsult, File, Dir, Opts),
+	'$loaded'(Stream, UserFile, SourceModule, ParentF, Line, Reconsult0, Reconsult, File, Dir, Opts),
 	working_directory(OldD, Dir),
 	H0 is heapused, '$cputime'(T0,_),
 	'$set_current_loop_stream'(OldStream, Stream),
@@ -681,18 +687,19 @@ db_files(Fs) :-
 	    '$skip_unix_header'(Stream)
 	  ;
 	    true
-	  ),
-	 '$loop'(Stream,Reconsult),
-	 '$lf_opt'(imports, TOpts, Imports),
-	 '$import_to_current_module'(File, ContextModule, Imports, _, TOpts),
-	 '$end_consult',
-	 '$q_do_save_file'(File, UserFile, ContextModule, TOpts ),
-	H is heapused-H0, '$cputime'(TF,_), T is TF-T0,
+	),
+	'$loop'(Stream,Reconsult),
+	'$lf_opt'(imports, TOpts, Imports),
+	'$import_to_current_module'(File, ContextModule, Imports, _, TOpts),
 	'$current_module'(Mod, SourceModule),
+	H is heapused-H0, '$cputime'(TF,_), T is TF-T0,
+	print_message(Verbosity, loaded(EndMsg, File, Mod, T, H)),
+	'$end_consult',
+	'$q_do_save_file'(File, UserFile, TOpts ),
 	( 
 	    Reconsult = reconsult ->
-	    '$clear_reconsulting'
-	;
+		'$clear_reconsulting'
+	    ;
 	    true
 	),
 	'$set_current_loop_stream'(Stream, OldStream),
@@ -712,13 +719,14 @@ db_files(Fs) :-
 	% format( 'O=~w~n', [Mod=UserFile] ),
 	!.
 
-'$q_do_save_file'(File, UserF, ContextModule, TOpts ) :-
+'$q_do_save_file'(File, UserF, TOpts ) :-
     '$lf_opt'(qcompile, TOpts, QComp), 
+    '$lf_opt'('$source_pos', TOpts, Pos),
     ( QComp ==  auto ; QComp == large,  Pos > 100*1024),
     '$absolute_file_name'(UserF,[file_type(qly),solutions(first),expand(true)],F,load_files(File)),
     !,
     '$qsave_file_'( File, UserF, F ).
-'$q_do_save_file'(_File, _, _ContextModule, _TOpts ).
+'$q_do_save_file'(_File, _, _TOpts ).
 
 % are we in autoload and autoload_flag is false?
 '$msg_level'( TOpts, Verbosity) :-
@@ -752,7 +760,7 @@ db_files(Fs) :-
 '$bind_module'(_, load_files).
 '$bind_module'(Mod, use_module(Mod)).
 
-'$import_to_current_module'(File, ContextModule, Imports, RemainingImports, TOpts) :-
+'$import_to_current_module'(File, ContextModule, _Imports, _RemainingImports, _TOpts) :-
 	\+ recorded('$module','$module'(File, _Module, _, _ModExports, _),_),
 	% enable loading C-predicates from a different file
 	recorded( '$load_foreign_done', [File, M0], _),
@@ -761,7 +769,7 @@ db_files(Fs) :-
 '$import_to_current_module'(File, ContextModule, Imports, RemainingImports, TOpts) :-
 	recorded('$module','$module'(File, Module, _Source, ModExports, _),_),
 	Module \= ContextModule, !,
-%	'$lf_opt'('$call', TOpts, Call),
+	'$lf_opt'('$call', TOpts, Goal),
 	'$convert_for_export'(Imports, ModExports, Module, ContextModule, TranslationTab, RemainingImports, Goal),
 	'$add_to_imports'(TranslationTab, Module, ContextModule).
 '$import_to_current_module'(_, _, _, _, _).
@@ -797,7 +805,6 @@ db_files(Fs) :-
 	  '$system_catch'(('$user_call'(G,M) -> true), M, Error, user:'$LoopError'(Error, top)),
 	  fail
 	;
-          OldMode = on,
 	  fail
 	).
 '$exec_initialisation_goals' :-
@@ -837,7 +844,7 @@ include(+ _F_) is directive
 	),
 	'$set_current_loop_stream'(OldStream, Stream),
 	H0 is heapused, '$cputime'(T0,_),
-	'$loaded'(Stream, X, Mod, F, L, include, Y, _Dir, []),
+	'$loaded'(Stream, X, Mod, F, L, include, _, Y, _Dir, []),
 	( '$nb_getval'('$included_file', OY, fail ) -> true ; OY = [] ),
 	'$lf_opt'(encoding, TOpts, Encoding),
 	'$set_encoding'(Stream, Encoding),
@@ -987,10 +994,10 @@ prolog_load_context(term_position, Position) :-
 %	format( 'IL=~w~n', [(F1:Imports->M)] ),
 	'$import_to_current_module'(F1, M, Imports, _, TOpts).
 
-'$ensure_file_loaded'(F, M, F1) :-
+'$ensure_file_loaded'(F, _M, F1) :-
 	recorded('$module','$module'(F1,_NM,_Source,_P,_),_),
 	recorded('$lf_loaded','$lf_loaded'(F1, _, _),_),
-	same_file(F1,F), !.
+	same_file(F1, F), !.
 '$ensure_file_loaded'(F, M, F1) :-
 	% loaded from the same module, but does not define a module.
 	recorded('$lf_loaded','$lf_loaded'(F1, _, M),_),
@@ -1005,7 +1012,8 @@ prolog_load_context(term_position, Position) :-
 %	format( 'IU=~w~n', [(F1:Imports->M)] ),
 	'$import_to_current_module'(F1, M, Imports, _, TOpts).
 
-'$ensure_file_unchanged'(F, M, F1) :-
+% module can be reexported.
+'$ensure_file_unchanged'(F, _M, F1) :-
 	recorded('$module','$module'(F1,_NM,_,_P,_),_),
 	recorded('$lf_loaded','$lf_loaded'(F1,Age,_),R),
 	same_file(F1,F), !,
@@ -1021,14 +1029,38 @@ prolog_load_context(term_position, Position) :-
 
 
 % inform the file has been loaded and is now available.
-'$loaded'(Stream, UserFile, M, OldF, Line, Reconsult, F, Dir, Opts) :-
+'$loaded'(Stream, UserFile, M, OldF, Line, Reconsult0, Reconsult, F, Dir, Opts) :-
 	'$file_name'(Stream, F0),
 	( F0 == user_input, nonvar(UserFile) -> UserFile = F 
 	  ; F = F0 ),
 	( F == user_input -> working_directory(Dir,Dir) ; file_directory_name(F, Dir) ),
 	nb_setval('$consulting_file', F ),
-	( Reconsult \== consult, Reconsult \== not_loaded, Reconsult \== changed, recorded('$lf_loaded','$lf_loaded'(F, _,_),R), erase(R), fail ; var(Reconsult) -> Reconsult = consult ; true ),
-	( Reconsult \== consult, recorded('$lf_loaded','$lf_loaded'(F, _, _, _, _, _, _),R), erase(R), fail ; var(Reconsult) -> Reconsult = consult ; true ),
+	( 
+	    Reconsult0 \== consult,
+	    Reconsult0 \== not_loaded, 
+	    Reconsult \== changed, 
+	    recorded('$lf_loaded','$lf_loaded'(F, _,_),R), 
+	    erase(R), 
+	    fail 
+	    ; 
+	    var(Reconsult0)
+	    -> 
+	    Reconsult = consult 
+	    ;
+	    Reconsult = Reconsult0
+	),
+	( 
+	    Reconsult \== consult, 
+	    recorded('$lf_loaded','$lf_loaded'(F, _, _, _, _, _, _),R),
+	    erase(R), 
+	    fail 
+	    ; 
+	    var(Reconsult)
+	    ->
+		Reconsult = consult 
+	    ;
+	    Reconsult = Reconsult0
+	),
 	( F == user_input -> Age = 0 ; time_file64(F, Age) ),
 	( recordaifnot('$lf_loaded','$lf_loaded'( F, Age, M), _) -> true ; true ),
 	recorda('$lf_loaded','$lf_loaded'( F, M, Reconsult, UserFile, OldF, Line, Opts), _).
@@ -1142,7 +1174,7 @@ unload_file( F0 ) :-
 % eliminate multi-files;
 % get rid of file-only predicataes.
 '$unload_file'( FileName, _F0 ) :-
-    '$current_predicate_var'(A,Mod,P).
+    '$current_predicate_var'(_A,Mod,P),
     '$owner_file'(P,Mod,FileName),
     \+ '$is_multifile'(P,Mod),
     functor( P, Na, Ar),
@@ -1150,7 +1182,7 @@ unload_file( F0 ) :-
     fail.
 %next multi-file.
 '$unload_file'( FileName, _F0 ) :-
-    recorded('$lf_loaded','$lf_loaded'( F, Age, _), R),
+    recorded('$lf_loaded','$lf_loaded'( FileName, _Age, _), R),
     erase(R),
     fail.
 '$unload_file'( FileName, _F0 ) :-
@@ -1159,16 +1191,12 @@ unload_file( F0 ) :-
     erase(ClauseRef),
     fail.
 '$unload_file'( FileName, _F0 ) :-
-    recorded('$multifile_dynamic'(_,_,_), '$mf'(Na,A,M,FFileName,R), R1),
+    recorded('$multifile_dynamic'(_,_,_), '$mf'(_Na,_A,_M,FileName,R), R1),
     erase(R1),
     erase(R),
     fail.
 '$unload_file'( FileName, _F0 ) :-
-    recorded('$multifile_defs','$defined'(FileName,Name,Arity,Mod), R),
-    erase(R),
-    fail.
-'$unload_file'( FileName, _F0 ) :-
-    recorded('$multifile_defs','$defined'(FileName,Name,Arity,Mod), R),
+    recorded('$multifile_defs','$defined'(FileName,_Name,_Arity,_Mod), R),
     erase(R),
     fail.
 '$unload_file'( FileName, _F0 ) :-
@@ -1442,7 +1470,8 @@ initialization(G,OPT) :-
 	  '$do_error'(type_error(OPT),initialization(G,OPT))
 	).
 '$initialization'(G,now) :-
-	( call(G) -> true ; format(user_error,':- ~w:~w failed.~n',[M,G]) ).
+	( call(G) -> true ; 
+	  format(user_error,':- ~w failed.~n',[G]) ).
 '$initialization'(G,after_load) :-
 	'$initialization'(G).
 % ignore for now.
diff --git a/pl/control.yap b/pl/control.yap
index 37bc79ce7..cc9dfc2d9 100644
--- a/pl/control.yap
+++ b/pl/control.yap
@@ -146,7 +146,7 @@ notrace(G) :-
 	   '$debug_stop'( State ),
 	   '$call'(G1, CP, G, M),
 	   '$$save_by'(CP2),
-	   (CP == CP2 -> ! ; '$debug_state'( NState ), ( true ; '$debug_restart'(NStart), fail ) ),
+	   (CP == CP2 -> ! ; '$debug_state'( NState ), ( true ; '$debug_restart'(NState), fail ) ),
 	   '$debug_restart'( State )
      ;
 	'$debug_restart'( State ),
@@ -196,10 +196,8 @@ over  _G_.
 If you want  _G_ to be deterministic you should use if-then-else, as
 it is both more efficient and more portable.
 
- 
 */
 if(X,Y,Z) :-
-	yap_hacks:env_choice_point(CP0),
 	(
 	 CP is '$last_choice_pt',
 	 '$call'(X,CP,if(X,Y,Z),M),
@@ -372,9 +370,8 @@ setup_call_catcher_cleanup(Setup, Goal, Catcher, Cleanup) :-
 '$cleanup_exception'(Exception, _, _) :-
 	throw(Exception).
 
-'$safe_call_cleanup'(Goal, Cleanup, Catcher, Exception) :-
-	'$current_choice_point'(MyCP1),
-	'$coroutining':freeze_goal(Catcher, '$clean_call'(Active, Cleanup)),
+'$safe_call_cleanup'(Goal, Cleanup, Catcher, _Exception) :-
+	'$coroutining':freeze_goal(Catcher, '$clean_call'(_Active, Cleanup)),
 	(
 	 yap_hacks:trail_suspension_marker(Catcher),
 	 yap_hacks:enable_interrupts,
diff --git a/pl/corout.yap b/pl/corout.yap
index 1a0915c0e..f30095b7b 100644
--- a/pl/corout.yap
+++ b/pl/corout.yap
@@ -101,7 +101,7 @@ wake_delay(redo_dif(Done, X, Y)) :-
 wake_delay(redo_freeze(Done, V, Goal)) :-
 	redo_freeze(Done, V, Goal).
 wake_delay(redo_eq(Done, X, Y, Goal)) :-
-	redo_eq(Done, X, Y, Goal, G).
+	redo_eq(Done, X, Y, Goal, _G).
 wake_delay(redo_ground(Done, X, Goal)) :-
 	redo_ground(Done, X, Goal).
 
@@ -135,7 +135,7 @@ attribute_goals(Var) -->
 	{ get_attr(Var, '$coroutining', Delays) },
 	attgoal_for_delays(Delays, Var).
 	
-attgoal_for_delays([], V) --> [].
+attgoal_for_delays([], _V) --> [].
 attgoal_for_delays([G|AllAtts], V) -->
 	attgoal_for_delay(G, V),
 	attgoal_for_delays(AllAtts, V).
@@ -150,10 +150,10 @@ attgoal_for_delay(redo_freeze(Done, V, Goal), V) -->
 attgoal_for_delay(redo_eq(Done, X, Y, Goal), V) -->
 	{ var(Done), first_att(Goal, V) }, !,
 	[ prolog:when(X=Y,Goal) ].
-attgoal_for_delay(redo_ground(Done, X, Goal), V) -->
+attgoal_for_delay(redo_ground(Done, X, Goal), _V) -->
 	{ var(Done) },  !,
 	[ prolog:when(ground(X),Goal) ].
-attgoal_for_delay(_, V) --> [].
+attgoal_for_delay(_, _V) --> [].
 
 remove_when_declarations(when(Cond,Goal,_), when(Cond,NoWGoal)) :- !,
 	remove_when_declarations(Goal, NoWGoal).
@@ -380,7 +380,7 @@ prepare_goal_for_when(G, Mod, Mod:G).
 % when/5 and when_suspend succeds when there is need to suspend a goal
 %
 %
-when(V, G, Done, LG0, LGF) :- var(V), !,
+when(V, G, _Done, LG, LG) :- var(V), !,
 	'$do_error'(instantiation_error,when(V,G)).
 when(nonvar(V), G, Done, LG0, LGF) :-
 	when_suspend(nonvar(V), G, Done, LG0, LGF).
@@ -613,8 +613,8 @@ first_att(T, V) :-
 	term_variables(T, Vs),
 	check_first_attvar(Vs, V).
 
-check_first_attvar(V.Vs, V0) :- attvar(V), !, V == V0.
-check_first_attvar(_.Vs, V0) :-
+check_first_attvar([V|_Vs], V0) :- attvar(V), !, V == V0.
+check_first_attvar([_|Vs], V0) :-
 	check_first_attvar(Vs, V0).
 
 /**
diff --git a/pl/dbload.yap b/pl/dbload.yap
index a377d9745..d9fb466c0 100644
--- a/pl/dbload.yap
+++ b/pl/dbload.yap
@@ -35,7 +35,7 @@ dbload_from_stream(R, M0, Type) :-
 	    fail 
 	).
 
-close_dbload(R, exo) :-
+close_dbload(_R, exo) :-
 	retract(dbloading(Na,Arity,M,T,NaAr,_)),
 	nb_getval(NaAr,Size),
 	exo_db_get_space(T, M, Size, Handle),
@@ -44,9 +44,9 @@ close_dbload(R, exo) :-
 	fail.
 close_dbload(R, exo) :-
 	seek(R, 0, bof, _),
-	exodb_add_facts(R, M),
+	exodb_add_facts(R, _M),
 	fail.
-close_dbload(R, mega) :-
+close_dbload(_R, mega) :-
 	retract(dbloading(Na,Arity,M,T,NaAr,_)),
 	nb_getval(NaAr,Size),
 	dbload_get_space(T, M, Size, Handle),
@@ -55,7 +55,7 @@ close_dbload(R, mega) :-
 	fail.
 close_dbload(R, mega) :-
 	seek(R, 0, bof, _),
-	dbload_add_facts(R, M),
+	dbload_add_facts(R, _M),
 	fail.
 close_dbload(_, _) :- 
 	retractall(dbloading(_Na,_Arity,_M,_T,_NaAr,_Handle)),
diff --git a/pl/debug.yap b/pl/debug.yap
index 394f90abc..8cd74509d 100644
--- a/pl/debug.yap
+++ b/pl/debug.yap
@@ -117,19 +117,18 @@ mode and the existing spy-points, when the debugger is on.
 	 ),
 	 !,
 	 '$do_suspy_predicates_by_name'(NA,S,EM).
- '$suspy_predicates_by_name'(A,spy,M) :- !,
+'$suspy_predicates_by_name'(A,spy,M) :- !,
 	 print_message(warning,no_match(spy(M:A))).
- '$suspy_predicates_by_name'(A,nospy,M) :-
+'$suspy_predicates_by_name'(A,nospy,M) :-
 	 print_message(warning,no_match(nospy(M:A))).
 
- '$do_suspy_predicates_by_name'(A,S,M) :-
+'$do_suspy_predicates_by_name'(A,S,M) :-
 	 current_predicate(A,M:T),
 	 functor(T,A,N),
 	 '$do_suspy'(S, A, N, T, M).
- '$do_suspy_predicates_by_name'(A, S, M) :-
-	 recorded('$import','$import'(EM,M,T0,_,A,N),_),
-	 functor(T0,A0,N0),
-	 '$do_suspy'(S, A0, N0, T, EM).
+'$do_suspy_predicates_by_name'(A, S, M) :-
+	 recorded('$import','$import'(EM,M,_,T,A,N),_),
+	 '$do_suspy'(S, A, N, T, EM).
 
 
  %
@@ -217,7 +216,7 @@ The possible forms for  _P_ are the same as in `spy P`.
  nospy L :-
 	 '$current_module'(M),
 	 '$suspy'(L, nospy, M), fail.
- nospy _.
+nospy _.
 
 /** @pred nospyall 
 
@@ -226,18 +225,18 @@ Removes all existing spy-points.
 
  
 */
- nospyall :-
+nospyall :-
 	 '$init_debugger',
 	 prolog:debug_action_hook(nospyall), !.
- nospyall :-
+nospyall :-
 	 recorded('$spy','$spy'(T,M),_), functor(T,F,N), '$suspy'(F/N,nospy,M), fail.
- nospyall.
+nospyall.
 
  % debug mode -> debug flag = 1
 
- debug :-
+debug :-
 	 '$init_debugger',
-	 ( nb_getval('$spy_gn',L) -> true ; nb_setval('$spy_gn',1) ),
+	 ( nb_getval('$spy_gn',_) -> true ; nb_setval('$spy_gn',1) ),
 	 '$start_debugging'(on),
 	 print_message(informational,debug(debug)).
 
@@ -748,7 +747,7 @@ be lost.
 	'$loop_fail'(GoalNumber, G, Module, CalledFromDebugger).
 '$loop_spy_event'(error('$fail_spy'(GoalNumber),_), _, _, _, _) :- !,
 	throw(error('$fail_spy'(GoalNumber),[])).
-'$loop_spy_event'(error('$done_spy'(G0),_), GoalNumber, G, _, CalledFromDebugger) :-
+'$loop_spy_event'(error('$done_spy'(G0),_), GoalNumber, _G, _, CalledFromDebugger) :-
 	G0 >= GoalNumber, !,
 	'$continue_debugging'(zip, CalledFromDebugger).
 '$loop_spy_event'(error('$done_spy'(GoalNumber),_), _, _, _, _) :- !,
@@ -891,7 +890,7 @@ be lost.
 '$spycall'(G, M, CalledFromDebugger, InRedo) :-
 	'$spycall_expanded'(G, M, CalledFromDebugger, InRedo).
 
-'$spycall_expanded'(G, M, CalledFromDebugger, InRedo) :-
+'$spycall_expanded'(G, M, _CalledFromDebugger, InRedo) :-
 	'$flags'(G,M,F,F),
 	F /\ 0x08402000 =\= 0, !, % dynamic procedure, logical semantics, or source
 	% use the interpreter
diff --git a/pl/errors.yap b/pl/errors.yap
index 10cfca842..5a5fcb9b5 100644
--- a/pl/errors.yap
+++ b/pl/errors.yap
@@ -339,7 +339,7 @@ print_message(_, Term) :-
 	flush_output(user_output),
 	flush_output(user_error),
 	print_message_lines(Stream, LinePrefix, [nl|LinesF]).
-'$print_system_message'(Error, Level, Lines) :-
+'$print_system_message'(_Error, Level, Lines) :-
 	flush_output(user_output),
 	flush_output(user_error),
 	'$messages':prefix(Level, LinePrefix, Stream, LinesF, Lines), !,
diff --git a/pl/flags.yap b/pl/flags.yap
index 97d26dd45..0412ebfdd 100644
--- a/pl/flags.yap
+++ b/pl/flags.yap
@@ -691,24 +691,18 @@ yap_flag(index,X) :-
 	'$do_error'(domain_error(flag_value,index+X),yap_flag(index,X)).
 
 % do or do not indexation
-yap_flag(index_sub_term_search_depth,X) :- var(X),
-	'$access_yap_flags'(23, X), !.
-yap_flag(index_sub_term_search_depth,X,X)  :-
-	integer(X), X > 0,
-	'$set_yap_flags'(23,X1).
-yap_flag(index_sub_term_search_depth,X,X)  :-
-	\+ integer(X),
-	'$do_error'(type_error(integer,X),yap_flag(index_sub_term_search_depth,X)).
-yap_flag(index_sub_term_search_depth,X,X) :-
-	'$do_error'(domain_error(out_of_range,index_sub_term_search_depth+X),yap_flag(index_sub_term_search_depth,X)).
-
-% should match definitions in Yap.h
-'$transl_to_index_mode'(0, off).
-'$transl_to_index_mode'(1, single).
-'$transl_to_index_mode'(2, compact).
-'$transl_to_index_mode'(3, multi).
-'$transl_to_index_mode'(3, on). % default is multi argument indexing
-'$transl_to_index_mode'(4, max).
+yap_flag(index_sub_term_search_depth,X) :- 
+    var(X),
+    '$access_yap_flags'(23, X), !.
+yap_flag(index_sub_term_search_depth,X)  :-
+    integer(X),
+    X > 0,
+    '$set_yap_flags'(23,X).
+yap_flag(index_sub_term_search_depth,X)  :-
+    \+ integer(X),
+    '$do_error'(type_error(integer,X),yap_flag(index_sub_term_search_depth,X)).
+yap_flag(index_sub_term_search_depth,X) :-
+    '$do_error'(domain_error(out_of_range,index_sub_term_search_depth+X),yap_flag(index_sub_term_search_depth,X)).
 
 % tabling mode
 yap_flag(tabling_mode,Options) :- 
@@ -725,16 +719,6 @@ yap_flag(tabling_mode,Option) :-
 yap_flag(tabling_mode,Options) :-
    '$do_error'(domain_error(flag_value,tabling_mode+Options),yap_flag(tabling_mode,Options)).
 
-% should match with code in stdpreds.c
-'$transl_to_yap_flag_tabling_mode'(0,default).
-'$transl_to_yap_flag_tabling_mode'(1,batched).
-'$transl_to_yap_flag_tabling_mode'(2,local).
-'$transl_to_yap_flag_tabling_mode'(3,exec_answers).
-'$transl_to_yap_flag_tabling_mode'(4,load_answers).
-'$transl_to_yap_flag_tabling_mode'(5,local_trie).
-'$transl_to_yap_flag_tabling_mode'(6,global_trie).
-'$transl_to_yap_flag_tabling_mode'(7,coinductive).
-
 yap_flag(informational_messages,X) :- var(X), !,
 	 yap_flag(verbose, X).
 
@@ -933,27 +917,6 @@ yap_flag(single_var_warnings,X) :-
 
 yap_flag(system_options,X) :-
 	'$system_options'(X).
-
-'$system_options'(big_numbers) :-
-	'$has_bignums'.
-'$system_options'(coroutining) :-
-	'$yap_has_coroutining'.
-'$system_options'(depth_limit) :-
-	\+ '$undefined'(get_depth_limit(_), prolog).
-'$system_options'(low_level_tracer) :-
-	\+ '$undefined'(start_low_level_trace, prolog).
-'$system_options'(or_parallelism) :-
-	\+ '$undefined'('$c_yapor_start', prolog).
-'$system_options'(rational_trees) :-
-	'$yap_has_rational_trees'.
-'$system_options'(readline) :-
-	'$swi_current_prolog_flag'(readline, true).
-'$system_options'(tabling) :-
-	\+ '$undefined'('$c_table'(_,_,_), prolog).
-'$system_options'(threads) :-
-	\+ '$undefined'('$thread_join'(_), prolog).
-'$system_options'(wam_profiler) :-
-	\+ '$undefined'(reset_op_counters, prolog).
 	
 yap_flag(update_semantics,X) :-
 	var(X), !,
@@ -1081,6 +1044,46 @@ yap_flag(max_threads,X) :-
 yap_flag(max_threads,X) :-
 	'$do_error'(domain_error(flag_value,max_threads+X),yap_flag(max_threads,X)).
 
+% should match definitions in Yap.h
+'$transl_to_index_mode'(0, off).
+'$transl_to_index_mode'(1, single).
+'$transl_to_index_mode'(2, compact).
+'$transl_to_index_mode'(3, multi).
+'$transl_to_index_mode'(3, on). % default is multi argument indexing
+'$transl_to_index_mode'(4, max).
+
+
+% should match with code in stdpreds.c
+'$transl_to_yap_flag_tabling_mode'(0,default).
+'$transl_to_yap_flag_tabling_mode'(1,batched).
+'$transl_to_yap_flag_tabling_mode'(2,local).
+'$transl_to_yap_flag_tabling_mode'(3,exec_answers).
+'$transl_to_yap_flag_tabling_mode'(4,load_answers).
+'$transl_to_yap_flag_tabling_mode'(5,local_trie).
+'$transl_to_yap_flag_tabling_mode'(6,global_trie).
+'$transl_to_yap_flag_tabling_mode'(7,coinductive).
+
+'$system_options'(big_numbers) :-
+	'$has_bignums'.
+'$system_options'(coroutining) :-
+	'$yap_has_coroutining'.
+'$system_options'(depth_limit) :-
+	\+ '$undefined'(get_depth_limit(_), prolog).
+'$system_options'(low_level_tracer) :-
+	\+ '$undefined'(start_low_level_trace, prolog).
+'$system_options'(or_parallelism) :-
+	\+ '$undefined'('$c_yapor_start', prolog).
+'$system_options'(rational_trees) :-
+	'$yap_has_rational_trees'.
+'$system_options'(readline) :-
+	'$swi_current_prolog_flag'(readline, true).
+'$system_options'(tabling) :-
+	\+ '$undefined'('$c_table'(_,_,_), prolog).
+'$system_options'(threads) :-
+	\+ '$undefined'('$thread_join'(_), prolog).
+'$system_options'(wam_profiler) :-
+	\+ '$undefined'(reset_op_counters, prolog).
+
 '$yap_system_flag'(agc_margin).
 '$yap_system_flag'(chr_toplevel_show_store).
 '$yap_system_flag'(debugger_print_options).
@@ -1307,7 +1310,7 @@ create_prolog_flag(Name, Value, Options) :-
 '$check_flag_name'(Name, _) :-
 	atom(Name), !.
 '$check_flag_name'(Name, G) :-
-	'$do_error'(type_error(atom),G).
+	'$do_error'(type_error(atom,Name),G).
 	
 '$check_flag_options'(O, _, _, G) :-
 	var(O),
@@ -1316,11 +1319,11 @@ create_prolog_flag(Name, Value, Options) :-
 '$check_flag_options'([O1|Os], Domain, RW, G) :- !,
 	'$check_flag_optionsl'([O1|Os], Domain, RW, G).
 '$check_flag_options'(O, _, _, G) :-
-	'$do_error'(type_error(list),G).
+	'$do_error'(type_error(list,O),G).
 
 
-'$check_flag_optionsl'([], _, read_write, G).
-'$check_flag_optionsl'([V|Os], Domain, RW, G) :-
+'$check_flag_optionsl'([], _, read_write, _G).
+'$check_flag_optionsl'([V|_Os], _Domain, _RW, G) :-
 	var(V),
 	'$do_error'(instantiation_error,G).
 '$check_flag_optionsl'([type(Type)|Os], Domain, RW, G) :- !,
@@ -1329,7 +1332,7 @@ create_prolog_flag(Name, Value, Options) :-
 '$check_flag_optionsl'([access(Access)|Os], Domain, RW, G) :- !,
 	'$check_flag_access'(Access, RW, G),
 	'$check_flag_optionsl'(Os, Domain, _, G).
-'$check_flag_optionsl'(Os, Domain, RW, G) :-
+'$check_flag_optionsl'(Os, _Domain, _RW, G) :-
 	'$do_error'(domain_error(create_prolog_flag,Os),G).
 
 '$check_flag_type'(V, _, G) :-
@@ -1348,7 +1351,7 @@ create_prolog_flag(Name, Value, Options) :-
 	'$do_error'(instantiation_error,G).
 '$check_flag_access'(read_write, read_write, _) :- !.
 '$check_flag_access'(read_only, read_only, _) :- !.
-'$check_flag_type'(Atom, _, G) :-
+'$check_flag_access'(Atom, _, G) :-
 	'$do_error'(domain_error(create_prolog_flag_option(access),Atom),G).
 
 '$user_flag_value'(F, Val) :-
@@ -1376,7 +1379,7 @@ create_prolog_flag(Name, Value, Options) :-
 '$check_flag_value'(Value, _, G) :-
 	\+ ground(Value), !,
 	'$do_error'(instantiation_error,G).
-'$check_flag_value'(Value, Domain, G) :-
+'$check_flag_value'(Value, Domain, _G) :-
 	var(Domain), !,
 	'$flag_domain_from_value'(Value, Domain).
 '$check_flag_value'(_, term, _) :- !.
diff --git a/pl/hacks.yap b/pl/hacks.yap
index 81f8c27f3..b35ef912c 100644
--- a/pl/hacks.yap
+++ b/pl/hacks.yap
@@ -38,7 +38,7 @@ run_formats([Com-Args|StackInfo], Stream) :-
 	run_formats(StackInfo, Stream).
 
 display_stack_info(CPs,Envs,Lim,PC) :-
-	display_stack_info(CPs,Envs,Lim,CP,Lines,[]),
+	display_stack_info(CPs,Envs,Lim,PC,Lines,[]),
 	flush_output(user_output),
 	flush_output(user_error),
 	print_message_lines(user_error, '', Lines).
@@ -47,7 +47,7 @@ code_location(Info,Where,Location) :-
 	integer(Where) , !,
 	'$pred_for_code'(Where,Name,Arity,Mod,Clause),
 	construct_code(Clause,Name,Arity,Mod,Info,Location).
-code_location(Ixnfo,_,Info).
+code_location(Info,_,Info).
 
 construct_code(-1,Name,Arity,Mod,Where,Location) :- !,
 	number_codes(Arity,ArityCode),
@@ -157,7 +157,7 @@ list_of_qmarks(I,[?|L]) :-
 	list_of_qmarks(I1,L).
 
 
-beautify_hidden_goal('$yes_no'(G,Query), prolog) -->
+beautify_hidden_goal('$yes_no'(G,_Query), prolog) -->
 	!,
 	{ Call =.. [(?), G] },
 	[Call].
@@ -182,7 +182,7 @@ beautify_hidden_goal('$continue_with_command'(Command,V,P,G,Source),prolog) -->
 	['TopLevel'(Command,G,V,P,Source)].
 beautify_hidden_goal('$spycall'(G,M,InControl,Redo),prolog) -->
 	['DebuggerCall'(M:G, InControl, Redo)].
-beautify_hidden_goal('$do_spy'(Goal, Mod, CP, InControl),prolog) -->
+beautify_hidden_goal('$do_spy'(Goal, Mod, _CP, InControl),prolog) -->
 	['DebuggerCall'(Mod:Goal, InControl)].
 beautify_hidden_goal('$system_catch'(G,Mod,Exc,Handler),prolog) -->
 	[catch(Mod:G, Exc, Handler)].
@@ -200,7 +200,7 @@ beautify_hidden_goal('$load_files'(_,_,Name),prolog) -->
 	[Name].
 beautify_hidden_goal('$reconsult'(Files,Mod),prolog) -->
 	[reconsult(Mod:Files)].
-beautify_hidden_goal('$undefp'([M|G]),prolog) -->
+beautify_hidden_goal('$undefp'([Mod|G]),prolog) -->
 	['CallUndefined'(Mod:G)].
 beautify_hidden_goal('$undefp'(?),prolog) -->
 	['CallUndefined'(?:?)].
@@ -218,9 +218,9 @@ beautify_hidden_goal('$findall'(T,G,S,A),prolog) -->
 	[findall(T,G,S,A)].
 beautify_hidden_goal('$listing'(G,M,_Stream),prolog) -->
 	[listing(M:G)].
-beautify_hidden_goal('$call'(G,CP,?,M),prolog) -->
+beautify_hidden_goal('$call'(G,_CP,?,M),prolog) -->
 	[call(M:G)].
-beautify_hidden_goal('$call'(G,CP,G0,M),prolog) -->
+beautify_hidden_goal('$call'(_G,_CP,G0,M),prolog) -->
 	[call(M:G0)].
 beautify_hidden_goal('$current_predicate'(M,Na,Ar),prolog) -->
 	[current_predicate(M,Na/Ar)].
@@ -228,6 +228,6 @@ beautify_hidden_goal('$current_predicate_for_atom'(Name,M,Ar),prolog) -->
 	{ functor(P, Name, Ar) },
 	[current_predicate(Name,M:P)].
 beautify_hidden_goal('$list_clauses'(Stream,M,Pred),prolog) -->
-	[listing(M:Pred)].
+	[listing(Stream,M:Pred)].
 
 
diff --git a/pl/listing.yap b/pl/listing.yap
index e68153222..fbf8bfd12 100644
--- a/pl/listing.yap
+++ b/pl/listing.yap
@@ -64,7 +64,7 @@ listing(MV) :-
 listing(Stream, MV) :-
     strip_module( MV, M, I),
     '$mlisting'(Stream, I, M).
-listing(Stream, []) :- !.
+listing(_Stream, []) :- !.
 listing(Stream, [MV|MVs]) :- !,
     listing(Stream,  MV),
     listing(Stream, MVs).	    
@@ -74,9 +74,9 @@ listing(Stream, [MV|MVs]) :- !,
 	 ;
       atom(MV) -> MV/_ = NA, '$do_listing'(Stream, M, NA)
 	 ;
-      MV = N//Ar -> ( integer(Ar) -> Ar2 is Ar+2, NA is N/Ar2 ; '$do_listing'(Stream, Na/Ar2, M), Ar2 >= 2, Ar is Ar2-2 )
+      MV = N//Ar -> ( integer(Ar) -> Ar2 is Ar+2, NA is N/Ar2 ; '$do_listing'(Stream, NA/Ar2, M), Ar2 >= 2, Ar is Ar2-2 )
 	 ;
-      MV = N/Ar, ( atom(N) -> true ; var(N) ), ( integer(Ar) -> true ; var(A) )  -> '$do_listing'(Stream, M, MV)
+      MV = N/Ar, ( atom(N) -> true ; var(N) ), ( integer(Ar) -> true ; var(Ar) )  -> '$do_listing'(Stream, M, MV)
 	 ;
       MV = M1:PP ->  '$mlisting'(Stream, PP, M1)
 	 ;
@@ -160,7 +160,7 @@ listing(Stream, [MV|MVs]) :- !,
       format( Stream, ':- ~q:~q.~n', [M,PredDef])
      ),
      fail.
-'$list_clauses'(Stream, M, Pred) :-
+'$list_clauses'(Stream, _M, _Pred) :-
         nl( Stream ),
         fail.
 '$list_clauses'(Stream, M, Pred) :-
diff --git a/pl/load_foreign.yap b/pl/load_foreign.yap
index 618a07b41..dbaddc3d4 100644
--- a/pl/load_foreign.yap
+++ b/pl/load_foreign.yap
@@ -175,7 +175,7 @@ open_shared_object(File, Opts, Handle) :-
 	prolog_load_context(module, M),
 	ignore( recordzifnot( '$foreign', M:'$swi_foreign'(File,Opts, Handle), _) ).
 
-'$open_shared_opts'(Opts, G, OptsI) :-
+'$open_shared_opts'(Opts, G, _OptsI) :-
 	var(Opts), !,
 	'$do_error'(instantiation_error,G).
 '$open_shared_opts'([], _, 0) :- !.
diff --git a/pl/messages.yap b/pl/messages.yap
index 1879e853a..5e8fee21d 100644
--- a/pl/messages.yap
+++ b/pl/messages.yap
@@ -137,7 +137,7 @@ generate_message(M) -->
 
 stack_dump(error(_,_)) -->
 	{ fail }, 
-	{ recorded(sp_info,local_sp(P,CP,Envs,CPs),_) },
+	{ recorded(sp_info,local_sp(_P,CP,Envs,CPs),_) },
 	{ Envs = [_|_] ; CPs = [_|_] }, !,
 	[nl],
 	'$hacks':display_stack_info(CPs, Envs, 20, CP).
@@ -222,7 +222,7 @@ system_message(myddas_version(Version)) -->
 	[ 'MYDDAS version ~a' - [Version] ].
 system_message(yes) -->
 	[  'yes'  ].
-system_message(error,error(Msg,Info)) -->
+system_message(error(Msg,Info)) -->
 	( { var(Msg) } ; { var(Info)} ), !,
 	['bad error ~w' - [error(Msg,Info)]].
 system_message(error(consistency_error(Who),Where)) -->
@@ -233,8 +233,7 @@ system_message(error(domain_error(DomainType,Opt), Where)) -->
 	[ 'DOMAIN ERROR- ~w: ' - Where],
 	domain_error(DomainType, Opt).
 system_message(error(format_argument_type(Type,Arg), Where)) -->
-	[ 'FORMAT ARGUMENT ERROR- ~~~a called with ~w in ~w: ' - [Type,Arg,Where]],
-	domain_error(DomainType, Opt).
+	[ 'FORMAT ARGUMENT ERROR- ~~~a called with ~w in ~w: ' - [Type,Arg,Where]].
 system_message(error(existence_error(directory,Key), Where)) -->
 	[ 'EXISTENCE ERROR- ~w: ~w not an existing directory' - [Where,Key] ].
 system_message(error(existence_error(key,Key), Where)) -->
@@ -269,14 +268,14 @@ system_message(error(evaluation_error(zero_divisor), Where)) -->
 system_message(error(instantiation_error, Where)) -->
 	[ 'INSTANTIATION ERROR- ~w: expected bound value' - [Where] ].
 system_message(error(not_implemented(Type, What), Where)) -->
-	[ '~w not implemented- ~w' - [Type, What] ].
+	[ '~w: ~w not implemented- ~w' - [Where, Type, What] ].
 system_message(error(operating_system_error, Where)) -->
 	[ 'OPERATING SYSTEM ERROR- ~w' - [Where] ].
 system_message(error(out_of_heap_error, Where)) -->
 	[ 'OUT OF DATABASE SPACE ERROR- ~w' - [Where] ].
 system_message(error(out_of_stack_error, Where)) -->
 	[ 'OUT OF STACK SPACE ERROR- ~w' - [Where] ].
-vsystem_message(error(out_of_trail_error, Where)) -->
+system_message(error(out_of_trail_error, Where)) -->
 	[ 'OUT OF TRAIL SPACE ERROR- ~w' - [Where] ].
 system_message(error(out_of_attvars_error, Where)) -->
 	[ 'OUT OF STACK SPACE ERROR- ~w' - [Where] ].
@@ -385,7 +384,7 @@ system_message(error(unknown, Where)) -->
 	[ 'EXISTENCE ERROR- procedure ~w undefined' - [Where] ].
 system_message(error(unhandled_exception,Throw)) -->
 	[ 'UNHANDLED EXCEPTION - message ~w unknown' - [Throw] ].
-system_message(error(uninstantiation_error(TE), Where)) -->
+system_message(error(uninstantiation_error(TE), _Where)) -->
 	[ 'UNINSTANTIATION ERROR - expected unbound term, got ~q' - [TE] ].
 system_message(Messg) -->
 	[ '~q' - Messg ].
@@ -431,10 +430,10 @@ domain_error(predicate_spec, Opt) --> !,
 	[ '~w invalid predicate specifier' - [Opt] ].
 domain_error(radix, Opt) --> !,
 	[ 'invalid radix ~w' - [Opt] ].
-vdomain_error(read_option, Opt) --> !,
+domain_error(read_option, Opt) --> !,
 	[ '~w invalid option to read_term' - [Opt] ].
-domain_error(semantics_indicatior, Opt) --> !,
-	[ '~w expected predicate indicator, got ~w' - [Opt] ].
+domain_error(semantics_indicator, Opt) --> !,
+	[ 'predicate indicator, got ~w' - [Opt] ].
 domain_error(shift_count_overflow, Opt) --> !,
 	[ 'shift count overflow in ~w' - [Opt] ].
 domain_error(source_sink, Opt) --> !,
@@ -576,8 +575,8 @@ the  _Prefix_ is printed too.
 
  
 */
-prolog:print_message_lines(S, _, []) :- !.
-prolog:print_message_lines(S, P, [at_same_line|Lines]) :- !,
+prolog:print_message_lines(_S, _, []) :- !.
+prolog:print_message_lines(_S, P, [at_same_line|Lines]) :- !,
 	print_message_line(S, Lines, Rest),
 	prolog:print_message_lines(S, P, Rest).
 prolog:print_message_lines(S, kind(Kind), Lines) :- !,
@@ -670,7 +669,7 @@ pred_arity((H:-_),Name,Arity) :-
 pred_arity((H-->_),Name,Arity) :- !,
     nonvar(H),
     !,
-    functor(HL,Name,1),
+    functor(H,Name,A1),
     Arity is A1+2.
 pred_arity(H,Name,Arity) :-
     functor(H,Name,Arity).
diff --git a/pl/modules.yap b/pl/modules.yap
index d8cda1a32..c055fee00 100644
--- a/pl/modules.yap
+++ b/pl/modules.yap
@@ -481,12 +481,12 @@ of predicates.
 	recorda('$system_initialisation', source_mode(New,Old), _).
 
 '$add_module_on_file'(DonorMod, DonorF, SourceF, Exports) :-
-    recorded('$module','$module'(DonorF, DonorMod, _, _, _),R),
+    recorded('$module','$module'(OtherF, DonorMod, _, _, _),R),
     % the module has been found, are we reconsulting?
     (
 	DonorF \= OtherF
     ->
-        '$do_error'(permission_error(module,redefined,DonorMod, OtherFile, DonorF),module(Mod,Exports))
+        '$do_error'(permission_error(module,redefined,DonorMod, OtherF, DonorF),module(DonorMod,Exports))
     ;
       recorded('$module','$module'(DonorF,DonorMod, SourceF,  _, _), R),
       erase( R ),
@@ -508,7 +508,7 @@ of predicates.
    ( recorded('$module','$module'( DonorF, DonorM, _,DonorExports, _),_) -> true ; DonorF = user_input ),
     ( recorded('$module','$module'( HostF, HostM, SourceF, _, _),_) -> true ; HostF = user_input ),
     recorded('$module','$module'(HostF, HostM, _, AllExports, _Line), R), erase(R),
-    '$convert_for_export'(Exports, DonorExports, DonorM, HostM, TranslationTab, AllReExports, reexport(DonorF, Exports)),
+    '$convert_for_export'(Exports, DonorExports, DonorM, HostM, _TranslationTab, AllReExports, reexport(DonorF, Exports)),
     lists:append( AllReExports, AllExports, Everything0 ),
     sort( Everything0, Everything ),
     ( source_location(_, Line) -> true ; Line = 0 ),
@@ -576,10 +576,10 @@ source_module(Mod) :-
 %
 '$module_expansion'(H, H, H, _HM, _BM, _SM) :- var(H), !.
 '$module_expansion'((H:-B), (H:-B1), (H:-BOO), HM, BM, SM) :- !,
-	'$is_mt'(HM, H, SM, B, IB, MM),
+	'$is_mt'(HM, H, SM, B, IB),
 	'$module_u_vars'(H,UVars,HM),	 % collect head variables in
 					 % expanded positions
-	'$expand_modules'(IB, B1, BO, HM, BM, MM, UVars),
+	'$expand_modules'(IB, B1, BO, HM, BM, SM, UVars),
 	('$full_clause_optimisation'(H, SM, BO, BOO) ->
 	  true
 	  ;
@@ -633,7 +633,7 @@ source_module(Mod) :-
 %  d:b(X) :- a:c(a:X), a:d(X), e(X).
 %
 %
-%       head variables.
+%       head variab'$expand_modules'(M:G,G1,GO,HM,_M,_SM,HVars)les.
 %       goals or arguments/sub-arguments?
 % I cannot use call here because of format/3
 % modules:
@@ -642,6 +642,7 @@ source_module(Mod) :-
 % A6: head module (this is the one used in compiling and accessing).
 %
 %
+%'$expand_modules'(V,NG,NG,_,_,SM,HVars):- writeln(V), fail.
 '$expand_modules'(V,NG,NG,_,_,SM,HVars) :-
 	var(V), !,
 	( '$not_in_vars'(V,HVars)
@@ -707,7 +708,7 @@ expand_goal(G, G).
 '$do_expand'(M:G, HM, _BM, _SM,  HVars, M:GI) :- !,
 	 nonvar(M),
 	'$do_expand'(G, HM, M, M, HVars, GI).
-'$do_expand'(G, HM, BM, SM,  _HVars, GI) :-
+'$do_expand'(G, _HM, _BM, SM,  _HVars, GI) :-
 	(
 	 '$pred_exists'(goal_expansion(G,GI), SM),
 	 call(SM:goal_expansion(G, GI))
@@ -757,13 +758,13 @@ expand_goal(G, G).
 	GI \== G, !,
 	'$expand_modules'(GI, G1, GO, HM, BM, SM, HVars).
 '$complete_goal_expansion'(G, HM, BM, SM, G1, G2, _HVars) :-
-	'$all_system_predicate'(G, M, ORIG), !,
+	'$all_system_predicate'(G, BM, BM0), !,
 	% make built-in processing transparent.
-	'$match_mod'(G, M, ORIG, HM, G1),
-	'$c_built_in'(G1, M, Gi),
+	'$match_mod'(G, HM, BM0, SM, G1),
+	'$c_built_in'(G1, BM0, Gi),
 	Gi = G2.
 '$complete_goal_expansion'(G, HM, BM, SM, NG, NG, _) :-
-	'$match_mod'(G, BM, BM, HM, NG).
+	'$match_mod'(G, HM, BM, SM, NG).
 
 %'$match_mod'(G, GMod, GMod, NG) :- !,
 %	NG = G.
@@ -771,12 +772,12 @@ expand_goal(G, G).
     nonvar(G),
     '$system_predicate'(G,prolog),
 %    \+ '$is_metapredicate'(G, prolog),
-    \+ '$is_multifile'(G,H), 
+    \+ '$is_multifile'(G,M), 
     !. % prolog: needs no module info.
 % same module as head,  and body goal (I cannot get rid of qualifier before
 % meta-call.
-'$match_mod'(G, HMod, _, HM, G) :- HMod == HM, !.
-'$match_mod'(G, GMod, _, _,  GMod:G).
+'$match_mod'(G, HMod, BM, _HM, G) :- HMod == BM, !.
+'$match_mod'(G, _, GMod, _,  GMod:G).
 
 
 % be careful here not to generate an undefined exception.
@@ -951,7 +952,7 @@ meta_predicate declaration
 	arg(I,NG,NA),
 	I1 is I-1,
 	'$meta_expansion_loop'(I1, D, G, NG, HVars, HM, BM, SM).
-'$meta_expansion_loop'(I, D, G, NG, HVars, HM, BM, SM) :- 
+'$meta_expansion_loop'(I, D, G, NG, HVars, HM, BM, SM) :-
 	arg(I,G,A),
 	arg(I,NG,A),
 	I1 is I-1,
@@ -961,11 +962,11 @@ meta_predicate declaration
     var(G), !.
 '$meta_expansion0'(M:G, _HM, _BM, SM, G1, _HVars) :-
     var(M), !,
-    G1 = '$execute_wo_mod'(G,SM).
+    G1 = '$execute_wo_mod'(G,M).
 % support for all/3
 '$meta_expansion0'(same(G, P), HM, BM, SM, same(G1, P),HVars) :- !,
-    '$meta_expansion0'(G, _HM, BM, SM, G1,HVars).
-'$meta_expansion0'(G, HM, BM, SM, M1:G1,HVars) :-
+    '$meta_expansion0'(G, HM, BM, SM, G1,HVars).
+'$meta_expansion0'(G, _HM, _BM, SM, M1:G1,_HVars) :-
     strip_module(SM:G,M1,G1).
 
 
@@ -1003,9 +1004,9 @@ its parent goal.
 	NFlags is Fl \/ 0x200004,
 	'$flags'(P, M, Fl, NFlags).
 
-'$is_mt'(M, H, CM, B, (context_module(CM),B), CM) :-
+'$is_mt'(M, H, CM, B, (context_module(CM),B)) :-
 	'$module_transparent'(_, M, _, H), !.
-'$is_mt'(_M, _H, CM, B, B, CM).
+'$is_mt'(_M, _H, CM, B, B).
 
 % comma has its own problems.
 :- '$install_meta_predicate'(','(0,0), prolog).
@@ -1226,7 +1227,7 @@ export_list(Module, List) :-
 	'$simple_conversion'(Exports, Tab, E).
 '$simple_conversion'([F/N as NF|Exports], [F/N-NF/N|Tab], [NF/N|E]) :-
 	'$simple_conversion'(Exports, Tab, E).
-'$simple_conversion'([F//N as BF|Exports], [F/N2-NF/N2|Tab], [NF/N2|E]) :-
+'$simple_conversion'([F//N as NF|Exports], [F/N2-NF/N2|Tab], [NF/N2|E]) :-
 	N2 is N+1,
 	'$simple_conversion'(Exports, Tab, E).
 '$simple_conversion'([op(Prio,Assoc,Name)|Exports], [op(Prio,Assoc,Name)|Tab], [op(Prio,Assoc,Name)|E]) :-
@@ -1238,7 +1239,7 @@ export_list(Module, List) :-
 	->
 	  true
 	;
-	  '$bad_export'((N1/A1 as A2), Module, ContextModule)
+	  '$bad_export'((N1/A1 as N2), Module, ContextModule)
 	),
 	'$clean_conversion'(Ps, List, Module, ContextModule, Tab, MyExports, Goal).	
 '$clean_conversion'([N1/A1|Ps], List, Module, ContextModule, [N1/A1-N1/A1|Tab], [N1/A1|MyExports], Goal) :- !,
@@ -1344,7 +1345,7 @@ export_list(Module, List) :-
 '$do_import'( N/K-N1/K, Mod, ContextMod) :-
 	functor(G,N,K),
 	'$follow_import_chain'(Mod,G,M0,G0),
-	G0=..[N0|Args],
+	G0=..[ N|Args],
 	G1=..[N1|Args],
 	( '$check_import'(M0,ContextMod,N1,K) ->
 	  ( ContextMod = user ->
@@ -1371,7 +1372,7 @@ export_list(Module, List) :-
 	M2 \= M1,  !,
 	b_getval('$lf_status', TOpts),
 	'$lf_opt'(redefine_module, TOpts, Action),
-	'$redefine_action'(Action, M1, M2, M, ContextM, N/K).
+	'$redefine_action'(Action, M1, M2, Mod, ContextM, N/K).
 '$check_import'(_,_,_,_).
 
 '$redefine_action'(ask, M1, M2, M, _, N/K) :-
@@ -1384,7 +1385,7 @@ export_list(Module, List) :-
 '$redefine_action'(true, M1, _, _, _, _) :- !,
 	recorded('$module','$module'(F, M1, _, _MyExports,_Line),_),
 	unload_file(F).
-'$redefine_action'(false, M1, M2, M, ContextM, N/K) :-
+'$redefine_action'(false, M1, M2, _M, ContextM, N/K) :-
 	recorded('$module','$module'(F, ContextM, _, _MyExports,_Line),_),
 	'$current_module'(_, M2),
 	'$do_error'(permission_error(import,M1:N/K,redefined,M2),F).
@@ -1556,15 +1557,15 @@ unload_module(Mod) :-
 % remove imported modules
 unload_module(Mod) :-
     setof( M, recorded('$import',_G0^_G^_N^_K^_R^'$import'(Mod,M,_G0,_G,_N,_K),_R), Ms),
-    recorded('$module','$module'( _, Mod, _, _, Exports), R),
+    recorded('$module','$module'( _, Mod, _, _, Exports), _),
     lists:member(M, Ms),
     current_op(X, Y, M:Op),
     lists:member( op(X, Y, Op), Exports ),
     op(X, 0, M:Op),
     fail.
 unload_module(Mod) :-
-    recorded('$module','$module'( _, Mod, _, _, Exports), R),
-    lists:member( op(X, Y, Op), Exports ),
+    recorded('$module','$module'( _, Mod, _, _, Exports), _),
+    lists:member( op(X, _Y, Op), Exports ),
     op(X, 0, Mod:Op),
     fail.
 unload_module(Mod) :-
diff --git a/pl/preddecls.yap b/pl/preddecls.yap
index 3942b4912..e76b66f0c 100644
--- a/pl/preddecls.yap
+++ b/pl/preddecls.yap
@@ -179,7 +179,7 @@ Since YAP4.3.0 multifile procedures can be static or dynamic.
 **/
 multifile(P) :-
 	'$current_module'(OM),
-	'$multifile'(P, M).
+	'$multifile'(P, OM).
 
 '$multifile'(V, _) :- var(V), !,
 	'$do_error'(instantiation_error,multifile(V)).
diff --git a/pl/preds.yap b/pl/preds.yap
index ccf056c8f..c47efdea4 100644
--- a/pl/preds.yap
+++ b/pl/preds.yap
@@ -228,7 +228,7 @@ assert(C) :-
 	'$do_error'(instantiation_error,assert(Mod:V)).
 '$assert_dynamic'(M:C,_,Where,R,P) :- !,
 	'$assert_dynamic'(C,M,Where,R,P).
-'$assert_dynamic'((H:-G),M1,Where,R,P) :-
+'$assert_dynamic'((H:-_G),_M1,_Where,_R,P) :-
         var(H), !, '$do_error'(instantiation_error,P).
 '$assert_dynamic'(CI,Mod,Where,R,P) :-
 	'$expand_clause'(CI,C0,C,Mod,HM),
@@ -305,7 +305,7 @@ assertz_static(C) :-
 	'$do_error'(instantiation_error,assert(M:V)).
 '$assert_static'(M:C,_,Where,R,P) :- !,
 	'$assert_static'(C,M,Where,R,P).
-'$assert_static'((H:-G),M1,Where,R,P) :-
+'$assert_static'((H:-_G),_M1,_Where,_R,P) :-
 	var(H), !, '$do_error'(instantiation_error,P).
 '$assert_static'(CI,Mod,Where,R,P) :-
 	'$expand_clause'(CI,C0,C,Mod, HM),
@@ -599,7 +599,7 @@ retract(C) :-
 %	'$is_dynamic'(H,M), !,
 	F /\ 0x00002000 =:= 0x00002000, !,
 	'$recordedp'(M:H,(H:-B),R),
-	( F /\ 0x20000000  =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,MRef),MR), erase(MR), fail ; true),
+	( F /\ 0x20000000  =:= 0x20000000, recorded('$mf','$mf_clause'(_,_,_,_,MRef),MR), erase(MR), erase(MRef), fail ; true),
 	erase(R).
 '$retract2'(_, H,M,_,_) :- 	
 	'$undefined'(H,M), !,
@@ -748,7 +748,7 @@ dynamic procedures. Under other modes it will abolish any procedures.
 abolish(V) :- var(V), !,
 	'$do_error'(instantiation_error,abolish(V)).
 abolish(Mod:V) :- var(V), !,
-	'$do_error'(instantiation_error,abolish(M:V)).
+	'$do_error'(instantiation_error,abolish(Mod:V)).
 abolish(M:X) :- !,
 	'$abolish'(X,M).
 abolish(X) :- 
@@ -935,7 +935,7 @@ dynamic_predicate(P,Sem) :-
 '$expand_clause'((H:-B),C1,C2,Mod,HM) :- !,
 	strip_module(Mod:H, HM, H1),
 	'$current_module'(M),
-	'$module_expansion'((H1:-B), C1, C2, HM, BM, M),
+	'$module_expansion'((H1:-B), C1, C2, HM, M, M),
 	( get_value('$strict_iso',on) ->
 	    '$check_iso_strict_clause'(C1)
         ;
@@ -1319,11 +1319,11 @@ compile_predicates(Ps) :-
 '$compile_predicates'(M:Ps, _, Call) :-
 	'$compile_predicates'(Ps, M, Call).
 '$compile_predicates'([], _, _).
-'$compile_predicates'(P.Ps, M, Call) :-
-	'$compile_predicate'(P, M, Call).
+'$compile_predicates'([P|Ps], M, Call) :-
+	'$compile_predicate'(P, M, Call),
 	'$compile_predicates'(Ps, M, Call).
 
-'$compile_predicate'(P, M, Call) :-
+'$compile_predicate'(P, _M, Call) :-
 	var(P), !,
 	'$do_error'(instantiation_error,Call).
 '$compile_predicate'(M:P, _, Call) :-
diff --git a/pl/profile.yap b/pl/profile.yap
index 93d97fac8..aa5d4c3a9 100644
--- a/pl/profile.yap
+++ b/pl/profile.yap
@@ -220,7 +220,7 @@ showprofres(A) :-
 
 '$display_preds'(_, _, _, N, N) :- !.
 '$display_preds'([], _, _, _, _).
-'$display_preds'([0-_|_], _Tot, _SoFar, _I, N) :- !.
+'$display_preds'([0-_|_], _Tot, _SoFar, _I, _N) :- !.
 '$display_preds'([NSum-P|Ps], Tot, SoFar, I, N) :-
 	Sum is -NSum,
 	Perc is (100*Sum)/Tot,
diff --git a/pl/qly.yap b/pl/qly.yap
index 77b6e65bb..70432e8df 100755
--- a/pl/qly.yap
+++ b/pl/qly.yap
@@ -113,7 +113,7 @@ Saves an image of the current state of the YAP database in file
  _F_, and guarantee that execution of the restored code will start by
 trying goal  _G_.
 **/
-save_program(File, Goal) :-
+save_program(_File, Goal) :-
 	recorda('$restore_goal', Goal ,_R),	
 	fail.
 save_program(File, _Goal) :-
@@ -210,8 +210,8 @@ save_program(File, _Goal) :-
     '$do_error'(domain_error(qsave_program,Opt), G).
 
 % there is some ordering between flags.
-'$x_yap_flag'(goal, Goal).
-'$x_yap_flag'(language, V).
+'$x_yap_flag'(goal, _Goal).
+'$x_yap_flag'(language, _V).
 '$x_yap_flag'(M:unknown, V) :-
 	current_module(M),
 	yap_flag(M:unknown, V).
@@ -275,7 +275,7 @@ save_program(File, _Goal) :-
 	load_files(library(win_menu), [silent(true)]),
 	fail.
 '$init_from_saved_state_and_args' :-
-	recorded('$reload_foreign_libraries',G,R),
+	recorded('$reload_foreign_libraries',_G,R),
 	erase(R),
 	shlib:reload_foreign_libraries,
 	fail.
@@ -406,10 +406,11 @@ qsave_file(F0, State) :-
 
 '$qsave_file_'(File, UserF, _State) :- 
     ( File == user_input -> Age = 0 ; time_file64(File, Age) ),
+    '$current_module'(M),
     assert(user:'$file_property'( '$lf_loaded'( UserF, Age, M) ) ),
     '$set_owner_file'( '$file_property'( _ ), user, File ),
     fail.
-'$qsave_file_'(File, UserF, State) :- 
+'$qsave_file_'(File, UserF, _State) :- 
     recorded('$lf_loaded','$lf_loaded'( File, M, Reconsult, UserFile, OldF, Line, Opts), _),
     assert(user:'$file_property'( '$lf_loaded'( UserF, M, Reconsult, UserFile, OldF, Line, Opts) ) ),
     '$set_owner_file'( '$file_property'( _ ), user, File ),
@@ -440,7 +441,7 @@ qsave_file(F0, State) :-
 	setof(Info, '$fetch_multi_file_module'(File, Info), Multi_Files).
 
 '$fetch_multi_file_file'(FileName, (M:G :- Body)) :-
-	recorded('$multifile_defs','$defined'(FileName,Name,Arity,Mod), _),
+	recorded('$multifile_defs','$defined'(FileName,Name,Arity,M), _),
 	functor(G, Name, Arity ), 
         clause(M:G, Body, ClauseRef),
 	clause_property(ClauseRef, file(FileName) ).
@@ -451,7 +452,7 @@ Saves an image of all the information compiled by the systemm on module _F_ to _
 **/
 
 qsave_module(Mod, OF) :- 
-	recorded('$module', '$module'(F,Mod,Source,Exps,L), _),
+	recorded('$module', '$module'(_F,Mod,Source,Exps,L), _),
 	'$fetch_parents_module'(Mod, Parents),
 	'$fetch_imports_module'(Mod, Imps),
 	'$fetch_multi_files_module'(Mod, MFs),
@@ -508,6 +509,7 @@ qload_module(Mod) :-
 	Verbosity = informational
     ),
     StartMsg = loading_module,
+    EndMsg = module_loaded,
     '$current_module'(SourceModule, Mod),
     H0 is heapused, '$cputime'(T0,_),
     absolute_file_name( Mod, File, [expand(true),file_type(qly)]),
@@ -558,9 +560,8 @@ qload_module(Mod) :-
     '$install_term_expansions_module'(Mod, TEs),
     % last, export everything to the host: if the loading crashed you didn't actually do
     % no evil.
-    '$convert_for_export'(all, Exps, Mod, SourceModule, TranslationTab, AllExports0, qload_module),
-    '$add_to_imports'(TranslationTab, Mod, SourceModule), % insert ops, at least for now
-    sort( AllExports0, AllExports ).
+    '$convert_for_export'(all, Exps, Mod, SourceModule, TranslationTab, _AllExports0, qload_module),
+    '$add_to_imports'(TranslationTab, Mod, SourceModule). % insert ops, at least for now
 
 '$fetch_imports_module'(Mod, Imports) :-
 	findall(Info, '$fetch_import_module'(Mod, Info), Imports).
@@ -568,12 +569,12 @@ qload_module(Mod) :-
 % detect an import that is local to the module.
 '$fetch_import_module'(Mod, '$import'(Mod0,Mod,G0,G,N,K) - S) :-
 	recorded('$import', '$import'(Mod0,Mod,G0,G,N,K), _),
-	( recorded('$module','$module'(_, Mod0, S, _, _), R) -> true ; S = user_input ).
+	( recorded('$module','$module'(_, Mod0, S, _, _), _) -> true ; S = user_input ).
 
 '$fetch_parents_module'(Mod, Parents) :-
 	findall(Parent, prolog:'$parent_module'(Mod,Parent), Parents).
 
-'$fetch_module_transparents_module'(Mod, Mmodule_Transparents) :-
+'$fetch_module_transparents_module'(Mod, Module_Transparents) :-
 	findall(Info, '$fetch_module_transparent_module'(Mod, Info), Module_Transparents).
 
 % detect an module_transparenterator that is local to the module.
@@ -593,9 +594,9 @@ qload_module(Mod) :-
 % detect an multi_file that is local to the module.
 '$fetch_multi_file_module'(Mod, '$defined'(FileName,Name,Arity,Mod)) :-
 	recorded('$multifile_defs','$defined'(FileName,Name,Arity,Mod), _).
-'$fetch_multi_file_module'(Mod, '$mf_clause'(FileName,_Name,_Arity,_Module,Clause), _) :-
-    recorded('$mf','$mf_clause'(FileName,_Name,_Arity,_Module,ClauseRef), _),
-    instance(R, Clause ).
+'$fetch_multi_file_module'(Mod, '$mf_clause'(FileName,_Name,_Arity,Mod,Clause), _) :-
+    recorded('$mf','$mf_clause'(FileName,_Name,_Arity,Mod,ClauseRef), _),
+    instance(ClauseRef, Clause ).
 
 '$fetch_term_expansions_module'(Mod, TEs) :-
 	findall(Info, '$fetch_term_expansion_module'(Mod, Info), TEs).
@@ -644,7 +645,7 @@ qload_module(Mod) :-
 '$restore_load_files'([]).
 '$restore_load_files'([M-F0|Fs]) :-
     (
-	absolute_file_name( M, File, [expand(true),file_type(qly),access(read),file_errors(fail)])
+	absolute_file_name( M,_File, [expand(true),file_type(qly),access(read),file_errors(fail)])
     ->
         qload_module(M)
     ;
@@ -682,9 +683,9 @@ qload_module(Mod) :-
 '$do_foreign'('$swi_foreign'(File, Opts, Handle), More) :-
     open_shared_object(File, Opts, Handle, NewHandle),
     '$init_foreigns'(More, NewHandle).
-'$do_foreign'('$swi_foreign'(_,_), More).
+'$do_foreign'('$swi_foreign'(_,_), _More).
 
-'$init_foreigns'([], Handle, NewHandle).
+'$init_foreigns'([], _Handle, _NewHandle).
 '$init_foreigns'(['$swi_foreign'( Handle, Function )|More], Handle, NewHandle) :- 
     !,
     call_shared_object_function( NewHandle, Function),
@@ -706,6 +707,7 @@ qload_file( F0 ) :-
 	Verbosity = informational
     ),
     StartMsg = loading_module,
+    EndMsg = module_loaded,
     '$current_module'( SourceModule ),
     H0 is heapused, 
     '$cputime'(T0,_),
@@ -737,21 +739,21 @@ qload_file( F0 ) :-
     print_message(Verbosity, loaded(EndMsg, File, Mod, T, H)),
     '$exec_initialisation_goals'.
 
-'$qload_file'(S, SourceModule, F, FilePl, _F0, _ImportList) :-
+'$qload_file'(_S, SourceModule, _F, FilePl, _F0, _ImportList) :-
     recorded('$lf_loaded','$lf_loaded'( FilePl, _Age, SourceModule), _),
    !.
-'$qload_file'(S, SourceModule, F, FilePl, _F0, _ImportList) :-
+'$qload_file'(_S, SourceModule, _F, FilePl, _F0, _ImportList) :-
     ( FilePl == user_input -> Age = 0 ; time_file64(FilePl, Age) ),
     recorda('$lf_loaded','$lf_loaded'( FilePl, Age, SourceModule), _),
     fail.
 '$qload_file'(S, _SourceModule, _File, _FilePl, _F0, _ImportList) :-
     '$qload_file_preds'(S),
     fail.
-'$qload_file'(S, SourceModule, F, FilePl, _F0, _ImportList) :-
-    user:'$file_property'( '$lf_loaded'( _, Age, _ ) ),
+'$qload_file'(_S, SourceModule, F, _FilePl, _F0, _ImportList) :-
+    user:'$file_property'( '$lf_loaded'( F, Age, _ ) ),
     recordaifnot('$lf_loaded','$lf_loaded'( F, Age, SourceModule), _),
     fail.
-'$qload_file'(_S, SourceModule, _File, FilePl, F0, _ImportList) :-
+'$qload_file'(_S, _SourceModule, _File, FilePl, F0, _ImportList) :-
     b_setval('$source_file', F0 ),
     '$process_directives'( FilePl ),
     fail.
@@ -768,7 +770,7 @@ qload_file( F0 ) :-
     assert( Clause ),
     fail.
 '$process_directives'( FilePl ) :-
-    user:'$file_property'( directive( MG, Mode,  VL, Pos  ) ),
+    user:'$file_property'( directive( MG, _Mode,  VL, Pos  ) ),
     '$set_source'( FilePl, Pos ),
     strip_module(MG, M, G),
     '$process_directive'(G, reconsult, M, VL, Pos),
diff --git a/pl/signals.yap b/pl/signals.yap
index e627f03dd..19d168f9b 100644
--- a/pl/signals.yap
+++ b/pl/signals.yap
@@ -275,7 +275,7 @@ on_signal(Signal,OldAction,NewAction) :-
 	on_signal(Signal, OldAction, NewAction).
 on_signal(Signal,OldAction,default) :-
 	'$reset_signal'(Signal, OldAction).
-on_signal(Signal,OldAction,Action) :-
+on_signal(_Signal,_OldAction,Action) :-
 	var(Action), !,
 	throw(error(system_error,'Somehow the meta_predicate declarations of on_signal are subverted!')).
 on_signal(Signal,OldAction,Action) :-
@@ -318,8 +318,8 @@ alarm(Number, Goal, Left) :-
 	Secs is integer(Number),
 	USecs is integer((Number-Secs)*1000000) mod 1000000,
 	on_signal(sig_alarm, _, Goal),
-	'$alarm'(Interval, 0, Left, _).
-alarm(Interval.USecs, Goal, Left.LUSecs) :-
+	'$alarm'(Secs, USecs, Left, _).
+alarm([Interval|USecs], Goal, Left.LUSecs) :-
 	on_signal(sig_alarm, _, Goal),
 	'$alarm'(Interval, USecs, Left, LUSecs).
 
diff --git a/pl/statistics.yap b/pl/statistics.yap
index 4b3454999..81feaa817 100644
--- a/pl/statistics.yap
+++ b/pl/statistics.yap
@@ -289,9 +289,7 @@ statistics(stack_shifts,[NOfHO,NOfSO,NOfTO]) :-
 	'$inform_stack_overflows'(NOfSO,_),
 	'$inform_trail_overflows'(NOfTO,_).
 statistics(atoms,[NOf,SizeOf]) :-
-	'$statistics_atom_info'(NOf,SizeOf),
-	'$inform_stack_overflows'(NOfSO,_),
-	'$inform_trail_overflows'(NOfTO,_).
+	'$statistics_atom_info'(NOf,SizeOf).
 statistics(static_code,[ClauseSize, IndexSize, TreeIndexSize, ExtIndexSize, SWIndexSize]) :-
 	'$statistics_db_size'(ClauseSize, TreeIndexSize, ExtIndexSize, SWIndexSize),
 	IndexSize is TreeIndexSize+ ExtIndexSize+ SWIndexSize.
diff --git a/pl/tabling.yap b/pl/tabling.yap
index b43de28a5..22c862784 100644
--- a/pl/tabling.yap
+++ b/pl/tabling.yap
@@ -283,21 +283,21 @@ table(Pred) :-
 '$do_table'(Mod,Pred) :-
    '$do_error'(type_error(callable,Mod:Pred),table(Mod:Pred)).
 
-'$set_table'(Mod,PredFunctor,PredModeList) :-
+'$set_table'(Mod,PredFunctor,_PredModeList) :-
    '$undefined'('$c_table'(_,_,_),prolog), !,
    functor(PredFunctor, PredName, PredArity),
    '$do_error'(resource_error(tabling,Mod:PredName/PredArity),table(Mod:PredName/PredArity)).
 '$set_table'(Mod,PredFunctor,PredModeList) :-
    '$undefined'(PredFunctor,Mod), !,
    '$c_table'(Mod,PredFunctor,PredModeList).
-'$set_table'(Mod,PredFunctor,PredModeList) :-
+'$set_table'(Mod,PredFunctor,_PredModeList) :-
    '$flags'(PredFunctor,Mod,Flags,Flags),
    Flags /\ 0x00000040 =:= 0x00000040, !.
 '$set_table'(Mod,PredFunctor,PredModeList) :-
    '$flags'(PredFunctor,Mod,Flags,Flags),
    Flags /\ 0x1991F8C0 =:= 0,
    '$c_table'(Mod,PredFunctor,PredModeList), !.
-'$set_table'(Mod,PredFunctor,PredModeList) :-
+'$set_table'(Mod,PredFunctor,_PredModeList) :-
    functor(PredFunctor,PredName,PredArity), 
    '$do_error'(permission_error(modify,table,Mod:PredName/PredArity),table(Mod:PredName/PredArity)).
 
diff --git a/pl/threads.yap b/pl/threads.yap
index d328fdcdc..13cfd32fa 100644
--- a/pl/threads.yap
+++ b/pl/threads.yap
@@ -307,7 +307,7 @@ thread_create(Goal, Id, Options) :-
 	 '$thread_options'(LOpts, Alias, Stack, Trail, System, Detached, AtExit, Mod, G)
 	).
 
-'$thread_options'([], _, Stack, Trail, System, Detached, AtExit, M, _) :-
+'$thread_options'([], _, Stack, Trail, System, Detached, AtExit, _M, _) :-
 	recorded('$thread_defaults', [DefaultStack, DefaultTrail, DefaultSystem, DefaultDetached, DefaultAtExit], _),
 	( var(Stack) -> Stack = DefaultStack; true ),
 	( var(Trail) -> Trail = DefaultTrail; true ),
@@ -330,17 +330,17 @@ thread_create(Goal, Id, Options) :-
 	( \+ integer(System) -> '$do_error'(type_error(integer,System),G0) ; true ).
 '$thread_option'(detached(Detached), _, _, _, _, Detached, _, _, G0) :- !,
 	( Detached \== true, Detached \== false -> '$do_error'(domain_error(thread_option,Detached+[true,false]),G0) ; true ).
-'$thread_option'(at_exit(AtExit), _, _, _, _, _, AtExit, M, G0) :- !,
+'$thread_option'(at_exit(AtExit), _, _, _, _, _, AtExit, _M, G0) :- !,
 	( \+ callable(AtExit) -> '$do_error'(type_error(callable,AtExit),G0) ; true ).
 % succeed silently, like SWI.
-'$thread_option'(Option, _, _, _, _, _, _, _, G0).
+'$thread_option'(_Option, _, _, _, _, _, _, _, _G0).
 %	'$do_error'(domain_error(thread_option,Option),G0).
 
 '$record_alias_info'(_, Alias) :-
 	var(Alias), !.
 '$record_alias_info'(_, Alias) :-
 	recorded('$thread_alias', [_|Alias], _), !,
-	'$do_error'(permission_error(create,thread,alias(Alias)), Goal).
+	'$do_error'(permission_error(create,thread,alias(Alias)), create_thread).
 '$record_alias_info'(Id, Alias) :-
 	recorda('$thread_alias', [Id|Alias], _).
 
@@ -554,7 +554,7 @@ thread_exit(Term) :-
 thread_exit(Term) :-
 	throw('$thread_finished'(exited(Term))).
 
-'$run_at_thread_exit'(Id0) :-
+'$run_at_thread_exit'(_Id0) :-
 	'$thread_run_at_exit'(G, M),
 	catch(once(M:G), _, fail),
 	fail.
@@ -714,7 +714,7 @@ thread_property(Id, Prop) :-
 	).
 '$thread_property'(detached(Detached), Id) :-
 	( '$thread_detached'(Id,Detached) -> true ; Detached = false ).
-'$thread_property'(at_exit(M:G), Id) :-
+'$thread_property'(at_exit(M:G), _Id) :-
 	'$thread_run_at_exit'(G,M).
 '$thread_property'(stack(Stack), Id) :-
 	'$thread_stacks'(Id, Stack, _, _).
@@ -824,7 +824,7 @@ Prints a table of current threads and their status.
 
  */
 thread_statistics(Id, Key, Val) :-
-    format("not implemented yet~n",[]).
+    format("not implemented yet: ~w, ~w, ~w~n",[Id, Key, Val]).
 
 %% @}
 
diff --git a/pl/utils.yap b/pl/utils.yap
index 94aca6cd7..638b22a21 100644
--- a/pl/utils.yap
+++ b/pl/utils.yap
@@ -66,7 +66,7 @@ a postfix operator.
 	'$do_error'(domain_error(operator_priority,P),G).
 '$check_op'(_,T,_,G) :-
 	\+ atom(T), !,
-	'$do_error'(type_error(atom,P),G).
+	'$do_error'(type_error(atom,T),G).
 '$check_op'(_,T,_,G) :-
 	\+  '$associativity'(T), !,
 	'$do_error'(domain_error(operator_specifier,T),G).
@@ -80,7 +80,7 @@ a postfix operator.
 '$check_top_op'(P, T, V, G) :-
 	atom(V), !,
 	'$check_op_name'(P, T, V, G).
-'$check_top_op'(P, T, V, G) :-
+'$check_top_op'(_P, _T, V, G) :-
 	'$do_error'(type_error(atom,V),G).
 
  '$associativity'(xfx).
@@ -95,18 +95,18 @@ a postfix operator.
 '$check_module_for_op'(MOp, G, _) :-
 	var(MOp), !,
 	'$do_error'(instantiation_error,G).
-'$check_module_for_op'(M:V, G, _) :-
+'$check_module_for_op'(M:_V, G, _) :-
 	var(M), !,
 	'$do_error'(instantiation_error,G).
 '$check_module_for_op'(M:V, G, NV) :-
 	atom(M), !,
 	'$check_module_for_op'(V, G, NV).
-'$check_module_for_op'(M:V, G, _) :- !,
-	'$do_error'(type_error(atom,P),G).
-'$check_module_for_op'(V, G, V).
+'$check_module_for_op'(M:_V, G, _) :- !,
+	'$do_error'(type_error(atom,M),G).
+'$check_module_for_op'(V, _G, V).
 
-'$check_ops'(P, T, [], G) :- !.
-'$check_ops'(P, T, Op.NV, G) :- !,
+'$check_ops'(_P, _T, [], _G) :- !.
+'$check_ops'(P, T, [Op|NV], G) :- !,
 	(
 	 var(NV)
 	->
@@ -116,7 +116,7 @@ a postfix operator.
 	 '$check_op_name'(P, T, NOp, G),
 	 '$check_ops'(P, T, NV, G)
 	).	
-'$check_ops'(P, T, Ops, G) :-
+'$check_ops'(_P, _T, Ops, G) :-
 	'$do_error'(type_error(list,Ops),G).
 
 '$check_op_name'(_,_,V,G) :-
@@ -147,7 +147,7 @@ a postfix operator.
 '$op'(P, T, A) :-
 	'$op2'(P,T,A).
 
-'$opl'(P, T, _, []).
+'$opl'(_P, _T, _, []).
 '$opl'(P, T, M, [A|As]) :-
 	'$op2'(P, T, M:A),
 	'$opl'(P, T, M, As).
@@ -316,10 +316,6 @@ simple(V) :- var(V), !.
 simple(A) :- atom(A), !.
 simple(N) :- number(N).
 
-callable(V) :- var(V), !, fail.
-callable(V) :- atom(V), !.
-callable(V) :- functor(V,_,Ar), Ar > 0.
-
 /** @pred  nth_instance(? _Key_,? _Index_,? _R_) 
 
 
diff --git a/pl/yio.yap b/pl/yio.yap
index 9077a914a..caa451c60 100644
--- a/pl/yio.yap
+++ b/pl/yio.yap
@@ -126,7 +126,7 @@ setting and clearing this flag are given under 7.7.
 	'$do_error'(instantiation_error,G).
 '$check_boolean'(true,_,_,_) :- !.
 '$check_boolean'(false,_,_,_) :- !.
-'$check_boolean'(X,B,T,G) :-
+'$check_boolean'(_X, B, T, G) :-
 	'$do_error'(domain_error(B,T),G).
 
 /** @defgroup IO_Sockets YAP Old Style Socket and Pipe Interface
@@ -209,7 +209,7 @@ socket_connect(Sock, Host, Read) :-
 	;
 	 true
 	),
-	yap_sockets:ip_socket(Domain, Type, Protocol, Sock).
+	yap_sockets:tcp_connect(Sock, Host:Read).
 
 /** @pred open_pipe_streams(Read, Write)
 
@@ -319,7 +319,7 @@ Like display/1, but using stream  _S_ to display the term.
  
 */
 display(Stream, T) :-
-	   write_term(Term, T, [ignore_ops(true)]).
+	   write_term(Stream, T, [ignore_ops(true)]).
 
 /* interface to user portray	*/
 '$portray'(T) :-
@@ -574,7 +574,7 @@ stream_position_data(Prop, Term, Value) :-
 '$set_default_expand'(false) :- !,
 	set_value('$open_expands_filename',false).
 '$set_default_expand'(V) :- !,
-	'$do_error'(domain_error(flag_value,V),yap_flag(open_expands_file_name,X)).
+	'$do_error'(domain_error(flag_value,V),yap_flag(open_expands_file_name,V)).
 
 %%! @}