diff --git a/C/absmi.c b/C/absmi.c
index f304edfe4..1ac585655 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -5396,10 +5396,10 @@ Yap_absmi(int inp)
       Op(write_x_loc, x);
       BEGD(d0);
       d0 = XREG(PREG->u.x.x);
+      PREG = NEXTOP(PREG, x);
       deref_head(d0, w_x_unk);
     w_x_bound:
       *SREG++ = d0;
-      PREG = NEXTOP(PREG, x);
       GONext();
 
       BEGP(pt0);
@@ -5409,7 +5409,6 @@ Yap_absmi(int inp)
 #else
       if (pt0 > H) {
 #endif
-	PREG = NEXTOP(PREG, x);
 	/* local variable: let us bind it to the list */
 #ifdef FROZEN_STACKS  /* TRAIL */
 	Bind_Local(pt0, Unsigned(SREG));
@@ -5422,7 +5421,6 @@ Yap_absmi(int inp)
 	GONext();
       }
       else {
-	PREG = NEXTOP(PREG, x);
 	*SREG++ = Unsigned(pt0);
 	GONext();
       }
@@ -11801,8 +11799,8 @@ Yap_absmi(int inp)
 	      goto execute_metacall;
 	      ENDP(pt1);
 	      ENDD(d1);
-	    } else {
-	      goto execute_metacall;
+	    } else if (mod != CurrentModule) {
+		goto execute_metacall;
 	    }
 	  }
 	  if (PRED_GOAL_EXPANSION_ON) {
@@ -11990,7 +11988,12 @@ Yap_absmi(int inp)
 		goto execute_comma;
 	      }
 	    } else {
-	      goto execute_metacall_after_comma;
+	      if (mod != CurrentModule)
+		goto execute_metacall_after_comma;
+	      else {
+		arity = pen->ArityOfPE;
+		goto execute_comma;
+	      }
 	    }
 
 	    BEGP(pt1);
@@ -12004,12 +12007,14 @@ Yap_absmi(int inp)
 	    ENDP(pt1);
 	    ENDD(d1);
 	  } else {
-	  execute_metacall_after_comma:
-	    ARG1 = ARG3 = d0;
-	    pen = PredMetaCall;
-	    ARG2 = Yap_cp_as_integer((choiceptr)ENV[E_CB]);
-	    ARG4 = ModuleName[mod];
-	    goto execute_after_comma;
+	    if (mod != CurrentModule) {
+	      execute_metacall_after_comma:
+	      ARG1 = ARG3 = d0;
+	      pen = PredMetaCall;
+	      ARG2 = Yap_cp_as_integer((choiceptr)ENV[E_CB]);
+	      ARG4 = ModuleName[mod];
+	      goto execute_after_comma;
+	    }
 	  }
 	}
       execute_comma:
diff --git a/C/depth_bound.c b/C/depth_bound.c
index e325baf41..606ca0552 100644
--- a/C/depth_bound.c
+++ b/C/depth_bound.c
@@ -51,10 +51,29 @@ static Int p_set_depth_limit(void)
   return(TRUE);
 }
 
+static Int p_set_depth_limit_for_next_call(void)
+{
+  Term d = Deref(ARG1);
+
+  if (IsVarTerm(d)) {
+    Yap_Error(INSTANTIATION_ERROR, d, "set-depth_limit");
+    return(FALSE);
+  } else if (!IsIntegerTerm(d)) {
+    Yap_Error(TYPE_ERROR_INTEGER, d, "set-depth_limit");
+    return(FALSE);
+  }
+  d = MkIntTerm(IntegerOfTerm(d)*2);
+
+  DEPTH = d;
+
+  return(TRUE);
+}
+
 void Yap_InitItDeepenPreds(void)
 {
   Yap_InitCPred("get_depth_limit", 1, p_get_depth_limit, SafePredFlag);
   Yap_InitCPred("$set_depth_limit", 1, p_set_depth_limit, 0);
+  Yap_InitCPred("$set_depth_limit_for_next_call", 1, p_set_depth_limit_for_next_call, 0);
 }
 
 #endif
diff --git a/C/exec.c b/C/exec.c
index 0eadcd3cb..ecd35defb 100644
--- a/C/exec.c
+++ b/C/exec.c
@@ -262,7 +262,7 @@ do_execute(Term t, SMALLUNSGN mod)
 	    YENV[-EnvSizeInCells-2]  = MkIntegerTerm((Int)PredPropByFunc(f,mod));
 	  }
 	} else {
-	    return CallMetaCall(mod);
+	  return CallMetaCall(mod);
 	}
 	YENV[E_CP] = (CELL)P;
 	YENV[E_CB] = (CELL)B;
@@ -277,9 +277,10 @@ do_execute(Term t, SMALLUNSGN mod)
 	P = NEXTOP(COMMA_CODE,sla);
 	t = ArgOfTerm(1,t);
 	goto restart_exec;
-      }
+    }  else if (mod != CurrentModule) {
       return(CallMetaCall(mod));
     }
+    }
     /* now let us do what we wanted to do from the beginning !! */
     /* I cannot use the standard macro here because
        otherwise I would dereference the argument and
@@ -384,7 +385,8 @@ p_execute_within(void)
 	    goto restart_exec;
 	  }
 	}
-	return(CallMetaCallWithin(mod, B));
+	if (mod != CurrentModule)
+	  return(CallMetaCallWithin(mod, B));
       }
       /* at this point check if we should enter creep mode */ 
       if (yap_flags[SPY_CREEP_FLAG]) {
@@ -1733,7 +1735,7 @@ Yap_InitExecFs(void)
   Yap_InitCPred("$call_with_args", 11, p_execute_9, 0);
   Yap_InitCPred("$call_with_args", 12, p_execute_10, 0);
 #ifdef DEPTH_LIMIT
-  Yap_InitCPred("$execute_under_depth_limit", 2, p_execute_depth_limit, 0);
+  Yap_InitCPred("depth_bound_call", 2, p_execute_depth_limit, 0);
 #endif
   Yap_InitCPred("$execute0", 2, p_execute0, 0);
   Yap_InitCPred("$save_current_choice_point", 1, p_save_cp, 0);
diff --git a/C/scanner.c b/C/scanner.c
index 761c30a84..de838f2d3 100644
--- a/C/scanner.c
+++ b/C/scanner.c
@@ -14,10 +14,6 @@
 * comments:	Prolog's scanner					 *
 *									 *
 *************************************************************************/
-#ifdef SCCS
-static char SccsId[] = "@(#)scanner.c	1.2";
-
-#endif
 
 /*
  * Description: 
diff --git a/pl/arith.yap b/pl/arith.yap
index 0db2ec343..9ad782773 100644
--- a/pl/arith.yap
+++ b/pl/arith.yap
@@ -30,24 +30,40 @@ compile_expressions :- '$set_value'('$c_arith',true).
 
 do_not_compile_expressions :- '$set_value'('$c_arith',[]).
 
-'$c_built_in'(IN, OUT) :-
+'$c_built_in'(IN, M, OUT) :-
 	'$get_value'('$c_arith',true), !,
-	'$do_c_built_in'(IN, OUT).
-'$c_built_in'(IN, IN).
+	'$do_c_built_in'(IN, M, OUT).
+'$c_built_in'(IN, _, IN).
 
 
-'$do_c_built_in'(Mod:G, Mod:GN) :- !,
-	'$do_c_built_in'(G, GN).
-'$do_c_built_in'(\+ G, OUT) :-
+'$do_c_built_in'(G, M, OUT) :- var(G), !,
+	'$do_c_built_in'(call(M:G),M,OUT).
+'$do_c_built_in'(Mod:G, _, GN) :- !,
+	'$do_c_built_in'(G, Mod, GN0),
+	(GN0 = (_,_) -> GN = GN0 ; GN = Mod:GN0).
+'$do_c_built_in'(\+ G, _, OUT) :-
 	nonvar(G),
 	G = (A = B),
 	!,
 	OUT = (A \= B).
-'$do_c_built_in'(call(G), OUT) :-
+'$do_c_built_in'(call(G), _, OUT) :-
 	nonvar(G),
 	G = (Mod:G1), !,
 	'$do_c_built_metacall'(G1, Mod, OUT).
-'$do_c_built_in'(recorded(K,T,R), OUT) :-
+'$do_c_built_in'(call(G), M, OUT) :-
+	var(G), !,
+	'$do_c_built_metacall'(G, M, OUT).
+'$do_c_built_in'(depth_bound_call(G,D), M, OUT) :- !,
+	'$do_c_built_in'(G, M, NG),
+	% make sure we don't have something like (A,B) -> $depth_next(D), A, B.
+	( '$composed_built_in'(NG) ->
+	    OUT = depth_bound_call(NG,D)
+	;
+	    OUT = ('$set_depth_limit_for_next_call'(D),NG)
+	).
+'$do_c_built_in'(once(G), M, ('$save_current_choice_point'(CP),NG,'$$cut_by'(CP))) :- !,
+	'$do_c_built_in'(G,M,NG).
+'$do_c_built_in'(recorded(K,T,R), _, OUT) :-
 	nonvar(K),
 	!,
 	( '$db_key'(K,I) ->
@@ -55,7 +71,7 @@ do_not_compile_expressions :- '$set_value'('$c_arith',[]).
 	;
 	    OUT = recorded(K,T,R)
 	).
-'$do_c_built_in'(X is Y, P) :-
+'$do_c_built_in'(X is Y, _, P) :-
 	nonvar(Y),		% Don't rewrite variables
 	!,
 	(
@@ -65,7 +81,7 @@ do_not_compile_expressions :- '$set_value'('$c_arith',[]).
 		'$drop_is'(X0, X, P1),
 		'$do_and'(P0, P1, P)
 	).
-'$do_c_built_in'(Comp0, R) :-		% now, do it for comparisons
+'$do_c_built_in'(Comp0, _, R) :-		% now, do it for comparisons
 	'$compop'(Comp0, Op, E, F),
 	!,
 	'$compop'(Comp,  Op, U, V),
@@ -73,7 +89,7 @@ do_not_compile_expressions :- '$set_value'('$c_arith',[]).
 	'$expand_expr'(F, Q, V),
 	'$do_and'(P, Q, R0),
 	'$do_and'(R0, Comp, R).
-'$do_c_built_in'(P, P).
+'$do_c_built_in'(P, _, P).
 
 '$do_c_built_metacall'(G1, Mod, call(Mod:G1)) :- 
 	var(G1), var(Mod), !.
@@ -106,7 +122,21 @@ do_not_compile_expressions :- '$set_value'('$c_arith',[]).
 '$compop'(X=:=Y,=:=, X, Y).
 '$compop'(X=\=Y,=\=, X, Y).
 
-
+'$composed_built_in'(V) :- var(V), !,
+	fail.
+'$composed_built_in'(('$save_current_choice_point'(_),NG,'$$cut_by'(_))) :- !,
+	'$composed_built_in'(NG).
+'$composed_built_in'((_,_)).
+'$composed_built_in'((_;_)).
+'$composed_built_in'((_|_)).
+'$composed_built_in'((_->_)).
+'$composed_built_in'(_:G) :-
+	'$composed_built_in'(G).
+'$composed_built_in'(\+G) :-
+	'$composed_built_in'(G).
+'$composed_built_in'(not(G)) :-
+	'$composed_built_in'(G).
+	
 % expanding an expression:
 % first argument is the expression not expanded,
 % second argument the expanded expression
diff --git a/pl/init.yap b/pl/init.yap
index 9077d0860..fc141a7c4 100644
--- a/pl/init.yap
+++ b/pl/init.yap
@@ -31,8 +31,8 @@ false :- fail.
 ';'(A,B) :- '$meta_call'((A;B),prolog).
 '|'(A,B) :- '$meta_call'((A;B),prolog).
 '->'(A,B) :- '$meta_call'((A->B),prolog).
-\+(G) :- '$meta_call'('\+'(G),prolog).
-\+(G) :- '$meta_call'(not(G),prolog).
+\+(G) :- '$meta_call'(\+(G),prolog).
+not(G) :- '$meta_call'(not(G),prolog).
 
 :- '$set_value'('$doindex',true).
 
diff --git a/pl/modules.yap b/pl/modules.yap
index bc2523f86..f04ba4c41 100644
--- a/pl/modules.yap
+++ b/pl/modules.yap
@@ -419,9 +419,9 @@ module(N) :-
 	'$pred_goal_expansion_on',
 	user:goal_expansion(G,M,GI), !,
 	'$module_expansion'(GI,G1,G2,M,CM,TM,HVars).
-'$complete_goal_expansion'(G, _, _, M, G, GF, _) :-
+'$complete_goal_expansion'(G, M, _, _, G, GF, _) :-
 	'$system_predicate'(G,M), !,
-	'$c_built_in'(G,GF).
+	'$c_built_in'(G,M,GF).
 '$complete_goal_expansion'(G, Mod, _, Mod, G, G, _) :- !.
 '$complete_goal_expansion'(G, GMod, _, _, GMod:G, GMod:G, _).