1145 lines
		
	
	
		
			34 KiB
		
	
	
	
		
			Prolog
		
	
	
	
	
	
			
		
		
	
	
			1145 lines
		
	
	
		
			34 KiB
		
	
	
	
		
			Prolog
		
	
	
	
	
	
%%% -*- Mode: Prolog; -*-
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% ProbLog inference
 | 
						|
% 
 | 
						|
% assumes probabilistic facts as Prob::Fact and clauses in normal Prolog format
 | 
						|
%
 | 
						|
% provides following inference modes (16/12/2008):
 | 
						|
% - approximation with interval width Delta (IJCAI07): problog_delta(+Query,+Delta,-Low,-High,-Status)
 | 
						|
% - bounds based on single probability threshold: problog_threshold(+Query,+Threshold,-Low,-High,-Status)
 | 
						|
% - as above, but lower bound only: problog_low(+Query,+Threshold,-Low,-Status)
 | 
						|
% - lower bound based on K most likely proofs: problog_kbest(+Query,+K,-Low,-Status)
 | 
						|
% - explanation probability (ECML07): problog_max(+Query,-Prob,-FactsUsed)
 | 
						|
% - exact probability: problog_exact(+Query,-Prob,-Status)
 | 
						|
% - sampling: problog_montecarlo(+Query,+Delta,-Prob)
 | 
						|
%
 | 
						|
%
 | 
						|
% angelika.kimmig@cs.kuleuven.be
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
:- module(problog, [problog_delta/5,
 | 
						|
	problog_threshold/5,
 | 
						|
	problog_low/4,
 | 
						|
	problog_kbest/4,
 | 
						|
	problog_kbest_save/6,
 | 
						|
	problog_max/3,
 | 
						|
	problog_exact/3,
 | 
						|
	problog_montecarlo/3,
 | 
						|
	get_fact_probability/2,
 | 
						|
	set_fact_probability/2,
 | 
						|
	get_fact/2,
 | 
						|
	tunable_fact/2,
 | 
						|
	non_ground_fact/1,
 | 
						|
	export_facts/1,
 | 
						|
	problog_help/0,
 | 
						|
	problog_dir/1,
 | 
						|
	set_problog_flag/2,
 | 
						|
	problog_flag/2,
 | 
						|
	problog_flags/0]).
 | 
						|
 | 
						|
:- style_check(all).
 | 
						|
:- yap_flag(unknown,error).
 | 
						|
 | 
						|
% problog related modules
 | 
						|
:- use_module('problog/flags',[set_problog_flag/2,
 | 
						|
	problog_flag/2,
 | 
						|
	problog_flags/0]).
 | 
						|
 | 
						|
:- use_module('problog/print', [print_sep_line/0,
 | 
						|
	print_inference/2]).
 | 
						|
 | 
						|
:- use_module('problog/tptree',[init_ptree/1,
 | 
						|
	delete_ptree/1,
 | 
						|
	insert_ptree/2,
 | 
						|
	count_ptree/2,
 | 
						|
	prune_check_ptree/2,
 | 
						|
	merge_ptree/3,
 | 
						|
	bdd_ptree_map/4,
 | 
						|
	bdd_ptree/3]).
 | 
						|
 | 
						|
% general yap modules
 | 
						|
:- ensure_loaded(library(lists)).
 | 
						|
:- ensure_loaded(library(terms)).
 | 
						|
:- ensure_loaded(library(random)).
 | 
						|
:- ensure_loaded(library(system)).
 | 
						|
:- ensure_loaded(library(rbtrees)).
 | 
						|
 | 
						|
% op attaching probabilities to facts
 | 
						|
:- op( 550, yfx, :: ).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% control predicates on various levels
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
% global over all inference methods, internal use only
 | 
						|
:- dynamic problog_predicate/2.
 | 
						|
% global over all inference methods, exported
 | 
						|
:- dynamic tunable_fact/2.
 | 
						|
:- dynamic non_ground_fact/1.
 | 
						|
:- dynamic problog_dir/1.
 | 
						|
% global, manipulated via problog_control/2
 | 
						|
:- dynamic up/0.
 | 
						|
:- dynamic limit/0.
 | 
						|
:- dynamic mc/0.
 | 
						|
:- dynamic remember/0.
 | 
						|
% local to problog_delta
 | 
						|
:- dynamic low/2.
 | 
						|
:- dynamic up/2.
 | 
						|
:- dynamic stopDiff/1.
 | 
						|
% local to problog_kbest
 | 
						|
:- dynamic current_kbest/3.
 | 
						|
% local to problog_max
 | 
						|
:- dynamic max_probability/1.
 | 
						|
:- dynamic max_proof/1.
 | 
						|
% local to problog_montecarlo
 | 
						|
:- dynamic mc_prob/1.
 | 
						|
% to keep track of the groundings for non-ground facts
 | 
						|
:- dynamic grounding_is_known/2.
 | 
						|
 | 
						|
% for fact where the proabability is a variable
 | 
						|
:- dynamic dynamic_probability_fact/1.
 | 
						|
:- dynamic dynamic_probability_fact_extract/2.
 | 
						|
 | 
						|
% directory where ProblogBDD executable is located
 | 
						|
% automatically set during loading -- assumes it is in same place as this file (problog.yap)
 | 
						|
%:- getcwd(PD),retractall(problog_dir(_)),assert(problog_dir(PD)).
 | 
						|
:- yap_flag(shared_object_search_path,PD),retractall(problog_dir(_)),assert(problog_dir(PD)).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% help
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_help :-
 | 
						|
	format('~2nProbLog inference currently offers the following inference methods:~n',[]),
 | 
						|
	show_inference,
 | 
						|
	format('~2nThe following global parameters are available:~n',[]),
 | 
						|
	problog_flags,
 | 
						|
	print_sep_line,
 | 
						|
	format('~n     use problog_help/0 to display this information~n',[]),
 | 
						|
	format('~n     use problog_flags/0 to display current parameter values~2n',[]),
 | 
						|
	print_sep_line,
 | 
						|
	nl,
 | 
						|
	flush_output.
 | 
						|
 | 
						|
show_inference :-
 | 
						|
	format('~n',[]),
 | 
						|
	print_sep_line,
 | 
						|
	print_inference(call,description),
 | 
						|
	print_sep_line,
 | 
						|
	print_inference('problog_delta(+Query,+Delta,-Low,-High,-Status)','approximation with interval width Delta (IJCAI07)'), 
 | 
						|
	print_inference('problog_threshold(+Query,+Threshold,-Low,-High,-Status)','bounds based on single probability threshold'), 
 | 
						|
	print_inference('problog_low(+Query,+Threshold,-Low,-Status)','lower bound based on single probability threshold'), 
 | 
						|
	print_inference('problog_kbest(+Query,+K,-Low,-Status)','lower bound based on K most likely proofs'), 
 | 
						|
	print_inference('problog_max(+Query,-Prob,-FactsUsed)','explanation probability (ECML07)'),
 | 
						|
	print_inference('problog_exact(+Query,-Prob,-Status)','exact probability'),
 | 
						|
	print_inference('problog_montecarlo(+Query,+Delta,-Prob)','sampling with 95\%-confidence-interval-width Delta'),
 | 
						|
	print_sep_line.
 | 
						|
	
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% initialization of global parameters
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
init_global_params :-
 | 
						|
	set_problog_flag(bdd_time,60), 
 | 
						|
	set_problog_flag(first_threshold,0.1), 
 | 
						|
	L is 10**(-30), 
 | 
						|
	set_problog_flag(last_threshold,L), 
 | 
						|
	set_problog_flag(id_stepsize,0.5), 
 | 
						|
	set_problog_flag(prunecheck,off), 
 | 
						|
	set_problog_flag(maxsteps,1000),
 | 
						|
	set_problog_flag(mc_batchsize,1000),
 | 
						|
	set_problog_flag(mc_logfile,'log.txt'),
 | 
						|
	set_problog_flag(bdd_file,example_bdd),
 | 
						|
	set_problog_flag(dir,output),
 | 
						|
	set_problog_flag(save_bdd,false),
 | 
						|
	set_problog_flag(verbose,true).
 | 
						|
%	problog_flags,
 | 
						|
%	print_sep_line,
 | 
						|
%	format('~n     use problog_help/0 for information~n',[]),
 | 
						|
%	format('~n     use problog_flags/0 to display current parameter values~2n',[]),
 | 
						|
%	print_sep_line,
 | 
						|
%	nl,
 | 
						|
%	flush_output.
 | 
						|
 | 
						|
% parameter initialization to be called after returning to user's directory:
 | 
						|
:- initialization(init_global_params).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% internal control flags
 | 
						|
% if on
 | 
						|
% - up: collect stopped derivations to build upper bound 
 | 
						|
% - limit: iterative deepening reached limit -> should go to next level
 | 
						|
% - mc: using problog_montecarlo, i.e. proving with current sample instead of full program
 | 
						|
% - remember: save BDD files containing script, params and mapping
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
problog_control(on,X) :-
 | 
						|
	call(X),!.
 | 
						|
problog_control(on,X) :-
 | 
						|
	assert(X).
 | 
						|
problog_control(off,X) :-
 | 
						|
	retractall(X).
 | 
						|
problog_control(check,X) :-
 | 
						|
	call(X).
 | 
						|
 | 
						|
:- problog_control(off,up).
 | 
						|
:- problog_control(off,mc).
 | 
						|
:- problog_control(off,limit).
 | 
						|
:- problog_control(off,remember).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% nice user syntax Prob::Fact
 | 
						|
% automatic translation to internal hardware access format
 | 
						|
%
 | 
						|
% probabilities =1 are dropped -> normal Prolog fact
 | 
						|
% 
 | 
						|
% internal fact representation 
 | 
						|
% - prefixes predicate name with problog_
 | 
						|
% - adds unique ID as first argument
 | 
						|
% - adds logarithm of probability as last argument
 | 
						|
% - keeps original arguments in between
 | 
						|
%
 | 
						|
% for each predicate appearing as probabilistic fact, wrapper clause is introduced:
 | 
						|
% - head is most general instance of original fact
 | 
						|
% - body is corresponding version of internal fact plus call to add_to_proof/2 to update current state during proving
 | 
						|
% example: edge(A,B) :- problog_edge(ID,A,B,LogProb), add_to_proof(ID,LogProb).
 | 
						|
%
 | 
						|
% dynamic predicate problog_predicate(Name,Arity) keeps track of predicates that already have wrapper clause
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
user:term_expansion(_P::( _Goal :- _Body ), _Error) :-
 | 
						|
	throw(error('we do not support this (yet?)!')).
 | 
						|
 | 
						|
user:term_expansion(P::Goal,Goal) :-
 | 
						|
	P \= t(_),
 | 
						|
	P =:= 1,
 | 
						|
	!.
 | 
						|
 | 
						|
user:term_expansion(P::Goal, problog:ProbFact) :- 
 | 
						|
	copy_term((P,Goal),(P_Copy,Goal_Copy)),
 | 
						|
	functor(Goal, Name, Arity),
 | 
						|
        atomic_concat([problog_,Name],ProblogName),
 | 
						|
	Goal =.. [Name|Args],
 | 
						|
	append(Args,[LProb],L1),
 | 
						|
	probclause_id(ID),
 | 
						|
	ProbFact =.. [ProblogName,ID|L1],
 | 
						|
	(
 | 
						|
	    (\+ var(P), P = t(TrueProb))
 | 
						|
	-> 
 | 
						|
	    (
 | 
						|
		assert(tunable_fact(ID,TrueProb)),
 | 
						|
		LProb is log(0.5)
 | 
						|
	    );
 | 
						|
	    (
 | 
						|
		ground(P)
 | 
						|
	    ->
 | 
						|
	        LProb is log(P);
 | 
						|
		(
 | 
						|
		    % Probability is a variable... check wether it appears in the term
 | 
						|
		    (
 | 
						|
			variable_in_term(Goal,P)
 | 
						|
		    ->
 | 
						|
		        true;
 | 
						|
			(
 | 
						|
			    format(user_error,'If you use probabilisitic facts with a variable as probabilility, the variable has to appear inside the fact.~n',[]),
 | 
						|
			    format(user_error,'You used ~q in your program.~2n',[P::Goal]),
 | 
						|
			    throw(non_ground_fact_error(P::Goal))
 | 
						|
			)
 | 
						|
		    ),
 | 
						|
		    LProb=log(P),
 | 
						|
		    assert(dynamic_probability_fact(ID)),
 | 
						|
		    assert(dynamic_probability_fact_extract(Goal_Copy,P_Copy))
 | 
						|
		)
 | 
						|
	    )
 | 
						|
        ),
 | 
						|
	(
 | 
						|
	    ground(Goal)
 | 
						|
	->
 | 
						|
	    true;
 | 
						|
	    assert(non_ground_fact(ID))
 | 
						|
	),
 | 
						|
	problog_predicate(Name, Arity, ProblogName).
 | 
						|
	    
 | 
						|
 | 
						|
% introduce wrapper clause if predicate seen first time
 | 
						|
problog_predicate(Name, Arity, _) :-
 | 
						|
	problog_predicate(Name, Arity), !.
 | 
						|
 | 
						|
problog_predicate(Name, Arity, ProblogName) :-
 | 
						|
	functor(OriginalGoal, Name, Arity),
 | 
						|
	OriginalGoal =.. [_|Args],
 | 
						|
	append(Args,[Prob],L1),
 | 
						|
	ProbFact =.. [ProblogName,ID|L1],
 | 
						|
	prolog_load_context(module,Mod),
 | 
						|
	
 | 
						|
	assert( (Mod:OriginalGoal :- ProbFact, 
 | 
						|
	                             (
 | 
						|
					 non_ground_fact(ID)
 | 
						|
				     ->
 | 
						|
				         (non_ground_fact_grounding_id(OriginalGoal,G_ID),
 | 
						|
					   atomic_concat([ID,'_',G_ID],ID2));
 | 
						|
					 ID2=ID
 | 
						|
				     ),
 | 
						|
				     % take the log of the probability (for non ground facts with variable as probability
 | 
						|
				     ProbEval is Prob,
 | 
						|
				     add_to_proof(ID2,ProbEval)
 | 
						|
		 )),
 | 
						|
 | 
						|
	assert( (Mod:problog_not(OriginalGoal) :- ProbFact,
 | 
						|
	                                          (
 | 
						|
						      non_ground_fact(ID)
 | 
						|
						  ->
 | 
						|
						     ( non_ground_fact_grounding_id(OriginalGoal,G_ID),
 | 
						|
						        atomic_concat([ID,'_',G_ID],ID2));
 | 
						|
						      ID2=ID
 | 
						|
						  ),
 | 
						|
						% take the log of the probability (for non ground facts with variable as probability
 | 
						|
						  ProbEval is Prob,
 | 
						|
						  add_to_proof_negated(ID2,ProbEval)
 | 
						|
		 )),
 | 
						|
	    
 | 
						|
	assert(problog_predicate(Name, Arity)),
 | 
						|
	ArityPlus2 is Arity+2,
 | 
						|
	dynamic(problog:ProblogName/ArityPlus2).	
 | 
						|
 | 
						|
% generate next global identifier
 | 
						|
probclause_id(ID) :-
 | 
						|
	nb_getval(probclause_counter,ID), !,
 | 
						|
	C1 is ID+1,
 | 
						|
	nb_setval(probclause_counter,C1), !.
 | 
						|
probclause_id(0) :-
 | 
						|
	nb_setval(probclause_counter,1).
 | 
						|
 | 
						|
non_ground_fact_grounding_id(Goal,ID) :-
 | 
						|
	(
 | 
						|
	    ground(Goal)
 | 
						|
	->
 | 
						|
	    true;
 | 
						|
	    (
 | 
						|
		format(user_error,'The current program uses non-ground facts.~n', []),
 | 
						|
		format(user_error,'If you query those, you may only query fully-grounded versions of the fact.~n',[]),
 | 
						|
		format(user_error,'Within the current proof, you queried for ~q which is not ground.~n~n', [Goal]),
 | 
						|
		throw(error(non_ground_fact(Goal)))
 | 
						|
	    )
 | 
						|
	),
 | 
						|
	(
 | 
						|
	    grounding_is_known(Goal,ID)
 | 
						|
	->
 | 
						|
	    true;
 | 
						|
	    (
 | 
						|
		nb_getval(non_ground_fact_grounding_id_counter,ID),
 | 
						|
		ID2 is ID+1,
 | 
						|
		nb_setval(non_ground_fact_grounding_id_counter,ID2),
 | 
						|
		assert(grounding_is_known(Goal,ID))
 | 
						|
	    )
 | 
						|
	).
 | 
						|
 | 
						|
reset_non_ground_facts :-
 | 
						|
	nb_setval(non_ground_fact_grounding_id_counter,0),
 | 
						|
	retractall(grounding_is_known(_,_)).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% access/update the probability of ID's fact
 | 
						|
% hardware-access version: naively scan all problog-predicates,
 | 
						|
% cut choice points if ID is ground (they'll all fail as ID is unique),
 | 
						|
% but not if it isn't (used to iterate over all facts when writing out probabilities for learning)
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
get_fact_probability(ID,Prob) :-
 | 
						|
	(
 | 
						|
	ground(ID) -> 
 | 
						|
		get_internal_fact(ID,ProblogTerm,_ProblogName,ProblogArity),!
 | 
						|
	;
 | 
						|
	get_internal_fact(ID,ProblogTerm,_ProblogName,ProblogArity)
 | 
						|
	),
 | 
						|
	arg(ProblogArity,ProblogTerm,Log),
 | 
						|
	Prob is exp(Log).
 | 
						|
set_fact_probability(ID,Prob) :-
 | 
						|
	get_internal_fact(ID,ProblogTerm,ProblogName,ProblogArity),
 | 
						|
	retract(ProblogTerm),  
 | 
						|
	ProblogTerm =.. [ProblogName|ProblogTermArgs],
 | 
						|
	nth(ProblogArity,ProblogTermArgs,_,KeepArgs),
 | 
						|
	NewLogProb is log(Prob),
 | 
						|
	nth(ProblogArity,NewProblogTermArgs,NewLogProb,KeepArgs),
 | 
						|
	NewProblogTerm =.. [ProblogName|NewProblogTermArgs],
 | 
						|
	assert(NewProblogTerm).
 | 
						|
 | 
						|
get_internal_fact(ID,ProblogTerm,ProblogName,ProblogArity) :-
 | 
						|
	problog_predicate(Name,Arity),   
 | 
						|
	atomic_concat([problog_,Name],ProblogName),
 | 
						|
	ProblogArity is Arity+2,
 | 
						|
	functor(ProblogTerm,ProblogName,ProblogArity),
 | 
						|
	arg(1,ProblogTerm,ID),
 | 
						|
	call(ProblogTerm).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% writing those facts with learnable parameters to File
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
export_facts(File) :-
 | 
						|
	tell(File),
 | 
						|
	export_facts,
 | 
						|
	flush_output,
 | 
						|
	told.
 | 
						|
export_facts :-
 | 
						|
	tunable_fact(ID,_),
 | 
						|
	once(write_tunable_fact(ID)),
 | 
						|
	fail.
 | 
						|
export_facts.
 | 
						|
 | 
						|
write_tunable_fact(ID) :-
 | 
						|
	get_internal_fact(ID,ProblogTerm,ProblogName,ProblogArity),
 | 
						|
	ProblogTerm =.. [_Functor,ID|Args],
 | 
						|
	atomic_concat('problog_',OutsideFunctor,ProblogName),
 | 
						|
	Last is ProblogArity-1,
 | 
						|
	nth(Last,Args,LogProb,OutsideArgs),
 | 
						|
	OutsideTerm =.. [OutsideFunctor|OutsideArgs],
 | 
						|
	Prob is exp(LogProb),
 | 
						|
	format('~w :: ~q.~n',[Prob,OutsideTerm]).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% recover fact for given id
 | 
						|
% list version not exported (yet?)
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% ID of ground fact
 | 
						|
get_fact(ID,OutsideTerm) :-
 | 
						|
	get_internal_fact(ID,ProblogTerm,ProblogName,ProblogArity),
 | 
						|
	!,
 | 
						|
	ProblogTerm =.. [_Functor,ID|Args],
 | 
						|
	atomic_concat('problog_',OutsideFunctor,ProblogName),
 | 
						|
	Last is ProblogArity-1,
 | 
						|
	nth(Last,Args,_LogProb,OutsideArgs),
 | 
						|
	OutsideTerm =.. [OutsideFunctor|OutsideArgs].
 | 
						|
% ID of instance of non-ground fact: get fact from grounding table
 | 
						|
get_fact(ID,OutsideTerm) :-
 | 
						|
	recover_grounding_id(ID,GID),
 | 
						|
	grounding_is_known(OutsideTerm,GID).
 | 
						|
 | 
						|
recover_grounding_id(Atom,ID) :-
 | 
						|
	name(Atom,List),
 | 
						|
	reverse(List,Rev),
 | 
						|
	recover_number(Rev,NumRev),
 | 
						|
	reverse(NumRev,Num),
 | 
						|
	name(ID,Num).
 | 
						|
recover_number([95|_],[]) :- !.  % name('_',[95])
 | 
						|
recover_number([A|B],[A|C]) :-
 | 
						|
	recover_number(B,C).
 | 
						|
 | 
						|
 | 
						|
get_fact_list([],[]).
 | 
						|
get_fact_list([ID|IDs],[Fact|Facts]) :-
 | 
						|
	(ID=not(X) -> Fact=not(Y); Fact=Y, ID=X),
 | 
						|
	get_fact(X,Y),
 | 
						|
	get_fact_list(IDs,Facts).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% ProbLog inference, core methods
 | 
						|
% 
 | 
						|
% state of proving saved in two backtrackable global variables
 | 
						|
% - problog_current_proof holds list of IDs of clauses used
 | 
						|
% - problog_probability holds the sum of their log probabilities
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
% called "inside" probabilistic facts to update current state of proving
 | 
						|
% if number of steps exceeded, fail
 | 
						|
% if fact used before, succeed and keep status as is
 | 
						|
% if not prunable, calculate probability and 
 | 
						|
%    if threshold exceeded, add stopped derivation to upper bound and fail 
 | 
						|
%       else update state and succeed
 | 
						|
add_to_proof(ID,Prob) :-
 | 
						|
	montecarlo_check(ID),
 | 
						|
	b_getval(problog_steps,MaxSteps),
 | 
						|
	b_getval(problog_probability, CurrentP),
 | 
						|
	nb_getval(problog_threshold, CurrentThreshold),
 | 
						|
	b_getval(problog_current_proof, IDs),
 | 
						|
 | 
						|
%%%% Bernd, changes for negated ground facts
 | 
						|
        \+ memberchk(not(ID),IDs),
 | 
						|
%%%% Bernd, changes for negated ground facts
 | 
						|
 | 
						|
	( MaxSteps =< 0 -> 
 | 
						|
	    fail
 | 
						|
	;
 | 
						|
	  ( memberchk(ID, IDs) ->
 | 
						|
	    true
 | 
						|
	  ;
 | 
						|
	    \+ prune_check([ID|IDs],1),
 | 
						|
	    multiply_probabilities(CurrentP, Prob, NProb),
 | 
						|
	    ( NProb < CurrentThreshold ->
 | 
						|
	      upper_bound([ID|IDs]),
 | 
						|
	      fail
 | 
						|
	    ;
 | 
						|
	      b_setval(problog_probability, NProb),
 | 
						|
	      b_setval(problog_current_proof, [ID|IDs])
 | 
						|
	    )
 | 
						|
	  ),
 | 
						|
	  Steps is MaxSteps-1,
 | 
						|
	  b_setval(problog_steps,Steps)
 | 
						|
	).
 | 
						|
 | 
						|
%%%% Bernd, changes for negated ground facts
 | 
						|
add_to_proof_negated(ID,Prob) :-
 | 
						|
	(
 | 
						|
	    problog_control(check,mc)
 | 
						|
	->
 | 
						|
	% the sample has to fail if the fact is negated
 | 
						|
	    \+ montecarlo_check(ID);
 | 
						|
	    true
 | 
						|
	),
 | 
						|
	b_getval(problog_steps,MaxSteps),
 | 
						|
	b_getval(problog_probability, CurrentP),
 | 
						|
	nb_getval(problog_threshold, CurrentThreshold),
 | 
						|
	b_getval(problog_current_proof, IDs),
 | 
						|
 | 
						|
        \+ memberchk(ID,IDs),
 | 
						|
	( MaxSteps =< 0 -> 
 | 
						|
	    fail
 | 
						|
	;
 | 
						|
	  ( memberchk(not(ID), IDs) ->
 | 
						|
	    true
 | 
						|
	  ;
 | 
						|
%	    \+ prune_check([ID|IDs],1),
 | 
						|
	    InverseProb is log(1 - exp(Prob)),
 | 
						|
	    multiply_probabilities(CurrentP, InverseProb, NProb),
 | 
						|
	    ( NProb < CurrentThreshold ->
 | 
						|
	      upper_bound([not(ID)|IDs]),   %% checkme
 | 
						|
	      fail
 | 
						|
	    ;
 | 
						|
	      b_setval(problog_probability, NProb),
 | 
						|
	      b_setval(problog_current_proof, [not(ID)|IDs])
 | 
						|
	    )
 | 
						|
	  ),
 | 
						|
	  Steps is MaxSteps-1,
 | 
						|
	  b_setval(problog_steps,Steps)
 | 
						|
	).
 | 
						|
%%%% Bernd, changes for negated ground facts
 | 
						|
 | 
						|
 | 
						|
% if in monte carlo mode, check array to see if fact can be used
 | 
						|
montecarlo_check(ID) :-
 | 
						|
	(
 | 
						|
	 problog_control(check,mc)
 | 
						|
	->
 | 
						|
	 (
 | 
						|
          array_element(mc_sample,ID,V),
 | 
						|
	  (
 | 
						|
	   V == 1 -> true
 | 
						|
	  ;
 | 
						|
	   V == 2 -> fail
 | 
						|
	  ;
 | 
						|
	   new_sample(ID)
 | 
						|
	  )
 | 
						|
	 )
 | 
						|
	;
 | 
						|
	  true
 | 
						|
	).
 | 
						|
 | 
						|
new_sample(ID) :-
 | 
						|
	get_fact_probability(ID,Prob),
 | 
						|
	random(R),
 | 
						|
	R<Prob,
 | 
						|
	!,
 | 
						|
        update_array(mc_sample,ID,1).
 | 
						|
new_sample(ID) :-
 | 
						|
        update_array(mc_sample,ID,2),
 | 
						|
        fail.
 | 
						|
 | 
						|
% if threshold reached, remember this by setting limit to on, then
 | 
						|
% if up is on, store stopped derivation in second trie
 | 
						|
% 
 | 
						|
% List always length>=1 -> don't need []=true-case for tries
 | 
						|
upper_bound(List) :-
 | 
						|
	problog_control(on,limit),
 | 
						|
	problog_control(check,up),
 | 
						|
	reverse(List,R),
 | 
						|
	(prune_check(R,2) -> true; insert_ptree(R,2)).
 | 
						|
 | 
						|
multiply_probabilities(CurrentLogP, LogProb, NLogProb) :-
 | 
						|
	NLogProb is CurrentLogP+LogProb.	
 | 
						|
 | 
						|
% this is called by all inference methods before the actual ProbLog goal
 | 
						|
% to set up environment for proving
 | 
						|
init_problog(Threshold) :-
 | 
						|
	reset_non_ground_facts,
 | 
						|
	LT is log(Threshold),
 | 
						|
	b_setval(problog_probability, 0.0),
 | 
						|
	b_setval(problog_current_proof, []),
 | 
						|
	nb_setval(problog_threshold, LT),
 | 
						|
	problog_flag(maxsteps,MaxS),
 | 
						|
	b_setval(problog_steps, MaxS),
 | 
						|
	problog_control(off,limit).
 | 
						|
 | 
						|
% idea: proofs that are refinements of known proof can be pruned as they don't add probability mass
 | 
						|
% note that current ptree implementation doesn't provide the check as there's no efficient method known so far...
 | 
						|
prune_check(Proof,TreeID) :-
 | 
						|
	problog_flag(prunecheck,on),
 | 
						|
	prune_check_ptree(Proof,TreeID).
 | 
						|
 | 
						|
% to call a ProbLog goal, patch all subgoals with the user's module context
 | 
						|
% (as logical part is there, but probabilistic part in problog)
 | 
						|
problog_call(Goal) :-
 | 
						|
	yap_flag(typein_module,Module),
 | 
						|
%%% if user provides init_db, call this before proving goal
 | 
						|
	(current_predicate(_,Module:init_db) -> call(Module:init_db); true),
 | 
						|
	put_module(Goal,Module,ModGoal),
 | 
						|
	call(ModGoal).
 | 
						|
 | 
						|
put_module((Mod:Goal,Rest),Module,(Mod:Goal,Transformed)) :-
 | 
						|
	!,
 | 
						|
	put_module(Rest,Module,Transformed).
 | 
						|
put_module((Goal,Rest),Module,(Module:Goal,Transformed)) :-
 | 
						|
	!,
 | 
						|
	put_module(Rest,Module,Transformed).
 | 
						|
put_module((Mod:Goal),_Module,(Mod:Goal)) :-
 | 
						|
	!.
 | 
						|
put_module(Goal,Module,Module:Goal).
 | 
						|
 | 
						|
% end of core
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% evaluating a DNF given as trie using BDD
 | 
						|
% input: ID of trie to be used
 | 
						|
% output: probability and status (to catch potential failures/timeouts from outside)
 | 
						|
% 
 | 
						|
% with internal BDD timeout (set using problog flag bdd_time)
 | 
						|
%
 | 
						|
% bdd_ptree/3 constructs files for ProblogBDD from the trie
 | 
						|
%
 | 
						|
% if calling ProblogBDD doesn't exit successfully, status will be timeout
 | 
						|
%
 | 
						|
% writes number of proofs in trie and BDD time to standard user output
 | 
						|
%
 | 
						|
% if remember is on, input files for ProblogBDD will be saved
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
eval_dnf(ID,Prob,Status) :- 
 | 
						|
	((ID = 1, problog_flag(save_bdd,true)) -> problog_control(on,remember); problog_control(off,remember)),
 | 
						|
	count_ptree(ID,NX),
 | 
						|
	(
 | 
						|
	    problog_flag(verbose,true)
 | 
						|
	->
 | 
						|
	(
 | 
						|
	    NX=1
 | 
						|
	->
 | 
						|
	    format(user,'1 proof~n',[]);
 | 
						|
            format(user,'~w proofs~n',[NX])
 | 
						|
	);
 | 
						|
	true
 | 
						|
        ),
 | 
						|
	problog_flag(dir,DirFlag),
 | 
						|
	problog_flag(bdd_file,BDDFileFlag),
 | 
						|
	atomic_concat([DirFlag,BDDFileFlag],BDDFile),
 | 
						|
	problog_flag(bdd_par_file,BDDParFileFlag),
 | 
						|
	atomic_concat([DirFlag,BDDParFileFlag],BDDParFile),
 | 
						|
	(problog_control(check,remember) ->
 | 
						|
	    bdd_ptree_map(ID,BDDFile,BDDParFile,Mapping),
 | 
						|
	    atomic_concat([DirFlag,'save_map'],MapFile),
 | 
						|
	    tell(MapFile),
 | 
						|
	    format('mapping(~q).~n',[Mapping]),
 | 
						|
	    flush_output,
 | 
						|
	    told
 | 
						|
	;
 | 
						|
	bdd_ptree(ID,BDDFile,BDDParFile)
 | 
						|
        ), 
 | 
						|
	problog_flag(bdd_time,BDDTime),
 | 
						|
	problog_flag(bdd_result,ResultFileFlag),
 | 
						|
	atomic_concat([DirFlag,ResultFileFlag],ResultFile),
 | 
						|
	problog_dir(PD),
 | 
						|
	atomic_concat([PD,'/ProblogBDD -l ',BDDFile,' -i ',BDDParFile,' -m p -t ', BDDTime,' > ', ResultFile],Command),
 | 
						|
	statistics(walltime,_),
 | 
						|
	shell(Command,Return), 
 | 
						|
	(
 | 
						|
	    Return =\= 0
 | 
						|
	->
 | 
						|
	    Status = timeout
 | 
						|
	;
 | 
						|
	    (
 | 
						|
		statistics(walltime,[_,E3]),
 | 
						|
		(problog_flag(verbose,true) -> format(user,'~w ms BDD processing~n',[E3]);true),
 | 
						|
		see(ResultFile),
 | 
						|
		read(probability(Prob)),
 | 
						|
		seen,
 | 
						|
		delete_file(ResultFile),
 | 
						|
		Status = ok
 | 
						|
	    )
 | 
						|
	),
 | 
						|
	(problog_control(check,remember) ->
 | 
						|
	    atomic_concat([DirFlag,'save_script'],SaveBDDFile),
 | 
						|
	    rename_file(BDDFile,SaveBDDFile),
 | 
						|
	    atomic_concat([DirFlag,'save_params'],SaveBDDParFile),
 | 
						|
	    rename_file(BDDParFile,SaveBDDParFile)
 | 
						|
	;
 | 
						|
	true
 | 
						|
        ),
 | 
						|
	problog_control(off,remember).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% different inference methods 
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% approximate inference: bounds based on single probability threshold
 | 
						|
% problog_threshold(+Goal,+Threshold,-LowerBound,-UpperBound,-Status)
 | 
						|
% 
 | 
						|
% use backtracking over problog_call to get all solutions
 | 
						|
%
 | 
						|
% trie 1 collects proofs, trie 2 collects stopped derivations, trie 3 is used to unit them for the upper bound
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_threshold(Goal, Threshold, _, _, _) :-
 | 
						|
	problog_control(on,up),
 | 
						|
	init_problog_threshold(Threshold),
 | 
						|
	problog_call(Goal),
 | 
						|
	add_solution,
 | 
						|
	fail.
 | 
						|
problog_threshold(_, _, LP, UP, Status) :-
 | 
						|
	compute_bounds(LP, UP, Status).
 | 
						|
 | 
						|
init_problog_threshold(Threshold) :-
 | 
						|
	init_ptree(1),
 | 
						|
	init_ptree(2),
 | 
						|
	init_problog(Threshold).
 | 
						|
 | 
						|
add_solution :-
 | 
						|
	b_getval(problog_current_proof, IDs),
 | 
						|
	(IDs == [] -> R = true ; reverse(IDs,R)),
 | 
						|
	insert_ptree(R,1).
 | 
						|
 | 
						|
compute_bounds(LP, UP, Status) :-
 | 
						|
	eval_dnf(1,LP,StatusLow),
 | 
						|
	(StatusLow \== ok ->
 | 
						|
	    Status = StatusLow
 | 
						|
	;
 | 
						|
	merge_ptree(1,2,3),
 | 
						|
	eval_dnf(3,UP,Status)),
 | 
						|
	delete_ptree(1),
 | 
						|
	delete_ptree(2),
 | 
						|
	delete_ptree(3).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% approximate inference: lower bound based on all proofs above probability threshold
 | 
						|
% problog_low(+Goal,+Threshold,-LowerBound,-Status)
 | 
						|
% 
 | 
						|
% same as problog_threshold/5, but lower bound only (no stopped derivations stored) 
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_low(Goal, Threshold, _, _) :-
 | 
						|
	problog_control(off,up),
 | 
						|
	init_problog_low(Threshold),
 | 
						|
	problog_call(Goal),
 | 
						|
	add_solution,
 | 
						|
	fail.
 | 
						|
problog_low(_, _, LP, Status) :-
 | 
						|
	eval_dnf(1,LP,Status),
 | 
						|
	delete_ptree(1).
 | 
						|
 | 
						|
init_problog_low(Threshold) :-
 | 
						|
	init_ptree(1),
 | 
						|
	init_problog(Threshold).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% approximate inference: bounds by iterative deepening up to interval width Delta
 | 
						|
% problog_delta(+Goal,+Delta,-LowerBound,-UpperBound,-Status)
 | 
						|
%
 | 
						|
% wraps iterative deepening around problog_threshold, i.e.
 | 
						|
% - starts with threshold given by first_threshold flag
 | 
						|
% - if Up-Low >= Delta, multiply threshold by factor given in id_stepsize flag and iterate
 | 
						|
% (does not use problog_threshold as trie 1 is kept over entire search)
 | 
						|
%
 | 
						|
% local dynamic predicates low/2, up/2, stopDiff/1
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_delta(Goal, Delta, Low, Up, Status) :-
 | 
						|
	problog_control(on,up),
 | 
						|
	problog_flag(first_threshold,InitT),
 | 
						|
	init_problog_delta(InitT,Delta),
 | 
						|
	problog_delta_id(Goal,Status),
 | 
						|
	delete_ptree(1),
 | 
						|
	delete_ptree(2),
 | 
						|
	(retract(low(_,Low)) -> true; true),
 | 
						|
	(retract(up(_,Up)) -> true; true).
 | 
						|
 | 
						|
 | 
						|
init_problog_delta(Threshold,Delta) :-
 | 
						|
	retractall(low(_,_)),
 | 
						|
	retractall(up(_,_)),
 | 
						|
	retractall(stopDiff(_)),
 | 
						|
	init_ptree(1),
 | 
						|
	init_ptree(2),
 | 
						|
	assert(low(0,0.0)),
 | 
						|
	assert(up(0,1.0)),
 | 
						|
	assert(stopDiff(Delta)),
 | 
						|
	init_problog(Threshold).
 | 
						|
 | 
						|
problog_delta_id(Goal, _) :-
 | 
						|
	problog_call(Goal),
 | 
						|
	add_solution,     % reused from problog_threshold
 | 
						|
	fail.
 | 
						|
problog_delta_id(Goal, Status) :-
 | 
						|
	evaluateStep(Ans,StatusE),
 | 
						|
	problog_flag(last_threshold_log,Stop),
 | 
						|
	nb_getval(problog_threshold,Min),
 | 
						|
	(StatusE \== ok ->
 | 
						|
	    Status = StatusE
 | 
						|
	;
 | 
						|
	(
 | 
						|
	    Ans = 1 ->
 | 
						|
	    Status = ok
 | 
						|
	;
 | 
						|
	    Min =<  Stop ->
 | 
						|
	    Status = stopreached
 | 
						|
	;
 | 
						|
	    problog_control(check,limit) ->
 | 
						|
	    problog_control(off,limit),
 | 
						|
	    problog_flag(id_stepsize_log,Step),
 | 
						|
	    New is Min+Step,
 | 
						|
	    nb_setval(problog_threshold,New),
 | 
						|
	    problog_delta_id(Goal, Status)
 | 
						|
	;
 | 
						|
	true
 | 
						|
	)).
 | 
						|
	
 | 
						|
% call the dnf evaluation where needed
 | 
						|
evaluateStep(Ans,Status)  :- once(evalStep(Ans,Status)).
 | 
						|
 | 
						|
evalStep(Ans,Status) :-
 | 
						|
	stopDiff(Delta),
 | 
						|
	count_ptree(1,NProofs),
 | 
						|
	count_ptree(2,NCands),
 | 
						|
	(problog_flag(verbose,true) -> format(user,'~w proofs, ~w stopped derivations~n',[NProofs,NCands]);true),
 | 
						|
	flush_output(user),
 | 
						|
	eval_lower(NProofs,Low,StatusLow),
 | 
						|
	(StatusLow \== ok ->
 | 
						|
	    Status = StatusLow
 | 
						|
	;
 | 
						|
	    up(_,OUP),
 | 
						|
	    IntDiff is OUP-Low,
 | 
						|
	    ((IntDiff < Delta; IntDiff =:= 0) -> 
 | 
						|
		Up=OUP, StatusUp = ok
 | 
						|
	    ;
 | 
						|
	        eval_upper(NCands,Up,StatusUp),
 | 
						|
		delete_ptree(2),
 | 
						|
		init_ptree(2),
 | 
						|
		delete_ptree(3)
 | 
						|
	    ),
 | 
						|
	    (StatusUp \== ok ->
 | 
						|
		Status = StatusUp
 | 
						|
	    ;
 | 
						|
	        Diff is Up-Low,
 | 
						|
		(problog_flag(verbose,true) -> format(user,'difference:  ~6f~n',[Diff]);true),
 | 
						|
		flush_output(user),
 | 
						|
		((Diff < Delta; Diff =:= 0) -> Ans = 1; Ans = 0),
 | 
						|
		Status = ok)).
 | 
						|
 | 
						|
% no need to re-evaluate if no new proofs found on this level
 | 
						|
eval_lower(N,P,ok) :-
 | 
						|
	low(N,P).
 | 
						|
% evaluate if there are proofs
 | 
						|
eval_lower(N,P,Status) :-
 | 
						|
	N > 0,
 | 
						|
	low(OldN,_),
 | 
						|
	N \= OldN,
 | 
						|
	eval_dnf(1,P,Status),
 | 
						|
	(Status = ok -> 
 | 
						|
	    retract(low(_,_)),
 | 
						|
	    assert(low(N,P)),
 | 
						|
	    (problog_flag(verbose,true) -> format(user,'lower bound: ~6f~n',[P]);true),
 | 
						|
	    flush_output(user)
 | 
						|
	;
 | 
						|
	true).
 | 
						|
 | 
						|
% if no stopped derivations, up=low
 | 
						|
eval_upper(0,P,ok) :-
 | 
						|
	retractall(up(_,_)),
 | 
						|
	low(N,P),
 | 
						|
	assert(up(N,P)).
 | 
						|
% else merge proofs and stopped derivations to get upper bound
 | 
						|
% in case of timeout or other problems, skip and use bound from last level
 | 
						|
eval_upper(N,UpP,ok) :-
 | 
						|
	N > 0,
 | 
						|
	merge_ptree(1,2,3),
 | 
						|
	eval_dnf(3,UpP,StatusUp),
 | 
						|
	(StatusUp = ok ->
 | 
						|
	    retract(up(_,_)),
 | 
						|
	    assert(up(N,UpP))
 | 
						|
	;
 | 
						|
	(problog_flag(verbose,true) -> format(user,'~w - continue using old up~n',[StatusUp]);true),
 | 
						|
	flush_output(user),
 | 
						|
	up(_,UpP)).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% explanation probability - returns list of facts used or constant 'unprovable' as third argument
 | 
						|
% problog_max(+Goal,-Prob,-Facts)
 | 
						|
%
 | 
						|
% uses iterative deepening with samw parameters as bounding algorithm
 | 
						|
% threshold gets adapted whenever better proof is found
 | 
						|
%
 | 
						|
% uses local dynamic predicates max_probability/1 and max_proof/1
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_max(Goal, Prob, Facts) :-
 | 
						|
	problog_control(off,up),
 | 
						|
	problog_flag(first_threshold,InitT),
 | 
						|
	init_problog_max(InitT),
 | 
						|
	problog_max_id(Goal, Prob, FactIDs),
 | 
						|
	( FactIDs = [_|_] -> get_fact_list(FactIDs,Facts);
 | 
						|
	    Facts = FactIDs).
 | 
						|
 | 
						|
init_problog_max(Threshold) :-
 | 
						|
	retractall(max_probability(_)),
 | 
						|
	retractall(max_proof(_)),
 | 
						|
	assert(max_probability(-999999)),
 | 
						|
	assert(max_proof(unprovable)),
 | 
						|
	init_problog(Threshold).
 | 
						|
 | 
						|
update_max :-
 | 
						|
	b_getval(problog_probability,CurrP),
 | 
						|
	max_probability(MaxP),
 | 
						|
	(CurrP =< MaxP ->
 | 
						|
	    fail
 | 
						|
	;
 | 
						|
	b_getval(problog_current_proof, IDs),
 | 
						|
	reverse(IDs,R),
 | 
						|
	retractall(max_proof(_)),
 | 
						|
	assert(max_proof(R)),
 | 
						|
	nb_setval(problog_threshold, CurrP),
 | 
						|
	retractall(max_probability(_)),
 | 
						|
	assert(max_probability(CurrP))).
 | 
						|
 | 
						|
problog_max_id(Goal, _Prob, _Clauses) :-
 | 
						|
	problog_call(Goal),
 | 
						|
	update_max,
 | 
						|
	fail.
 | 
						|
problog_max_id(Goal, Prob, Clauses) :-
 | 
						|
	max_probability(MaxP),
 | 
						|
	nb_getval(problog_threshold, LT),
 | 
						|
	problog_flag(last_threshold_log,ToSmall),
 | 
						|
	((MaxP >= LT ; \+ problog_control(check,limit); LT < ToSmall) ->
 | 
						|
	    ((max_proof(unprovable), problog_control(check,limit), LT < ToSmall) ->
 | 
						|
		problog_flag(last_threshold,Stopping),
 | 
						|
		Clauses = unprovable(Stopping) 
 | 
						|
	    ; max_proof(Clauses)),
 | 
						|
	   Prob is exp(MaxP)
 | 
						|
       ;
 | 
						|
	problog_flag(id_stepsize_log,Step),
 | 
						|
	NewLT is LT+Step,
 | 
						|
	nb_setval(problog_threshold, NewLT),
 | 
						|
	problog_control(off,limit),
 | 
						|
	problog_max_id(Goal, Prob, Clauses)).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% lower bound using k best proofs
 | 
						|
% problog_kbest(+Goal,+K,-Prob,-Status)
 | 
						|
%
 | 
						|
% does iterative deepening search similar to problog_max, but for k(>=1) most likely proofs
 | 
						|
% afterwards uses BDD evaluation to calculate probability (also for k=1 -> uniform treatment in learning)
 | 
						|
%
 | 
						|
% uses dynamic local predicate current_kbest/3 to collect proofs,
 | 
						|
% only builds trie at the end (as probabilities of single proofs are important here)
 | 
						|
%
 | 
						|
% note: >k proofs will be used if the one at position k shares its probability with others, 
 | 
						|
% as all proofs with that probability will be included 
 | 
						|
%
 | 
						|
% version with _save at the end  renames files for ProblogBDD to keep them
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
problog_kbest_save(Goal, K, Prob, Status, BDDFile, ParamFile) :-
 | 
						|
	problog_kbest(Goal, K, Prob, Status),
 | 
						|
	( Status=ok ->
 | 
						|
	    problog_flag(bdd_file,InternBDDFlag),
 | 
						|
	    problog_flag(bdd_par_file,InternParFlag),
 | 
						|
	    problog_flag(dir,DirFlag),
 | 
						|
	    atomic_concat([DirFlag,InternBDDFlag],InternBDD),
 | 
						|
	    atomic_concat([DirFlag,InternParFlag],InternPar),
 | 
						|
	    rename_file(InternBDD,BDDFile),
 | 
						|
	    rename_file(InternPar,ParamFile)
 | 
						|
	;
 | 
						|
	true).
 | 
						|
 | 
						|
problog_kbest(Goal, K, Prob, Status) :-
 | 
						|
	problog_control(off,up),
 | 
						|
	problog_flag(first_threshold,InitT),
 | 
						|
	init_problog_kbest(InitT),
 | 
						|
	problog_kbest_id(Goal, K),
 | 
						|
	retract(current_kbest(_,ListFound,_NumFound)),
 | 
						|
	build_prefixtree(ListFound),
 | 
						|
	eval_dnf(1,Prob,Status),
 | 
						|
	delete_ptree(1).
 | 
						|
 | 
						|
init_problog_kbest(Threshold) :-
 | 
						|
	retractall(current_kbest(_,_,_)),
 | 
						|
	assert(current_kbest(-999999,[],0)),  %(log-threshold,proofs,num_proofs)  
 | 
						|
	init_ptree(1),
 | 
						|
	init_problog(Threshold).
 | 
						|
 | 
						|
problog_kbest_id(Goal, K) :-
 | 
						|
	problog_call(Goal),
 | 
						|
	update_kbest(K),
 | 
						|
	fail.
 | 
						|
problog_kbest_id(Goal, K) :-
 | 
						|
	current_kbest(CurrentBorder,_,Found),
 | 
						|
	nb_getval(problog_threshold, Min),
 | 
						|
	problog_flag(last_threshold_log,ToSmall),
 | 
						|
	((Found>=K ; \+ problog_control(check,limit) ; Min < CurrentBorder ; Min < ToSmall) ->
 | 
						|
	   true
 | 
						|
       ;
 | 
						|
	problog_flag(id_stepsize_log,Step),
 | 
						|
	NewLT is Min+Step,
 | 
						|
	nb_setval(problog_threshold, NewLT),
 | 
						|
	problog_control(off,limit),
 | 
						|
	problog_kbest_id(Goal, K)).
 | 
						|
 | 
						|
update_kbest(K) :-
 | 
						|
	b_getval(problog_probability,NewLogProb),
 | 
						|
	current_kbest(LogThreshold,_,_),
 | 
						|
	(NewLogProb>=LogThreshold -> 
 | 
						|
	    b_getval(problog_current_proof,RevProof),
 | 
						|
	    reverse(RevProof,Proof),
 | 
						|
	    update_current_kbest(K,NewLogProb,Proof)
 | 
						|
	;
 | 
						|
	    fail).
 | 
						|
 | 
						|
update_current_kbest(_,NewLogProb,Cl) :-
 | 
						|
	current_kbest(_,List,_),
 | 
						|
	memberchk(NewLogProb-Cl,List),
 | 
						|
	!.
 | 
						|
update_current_kbest(K,NewLogProb,Cl) :-
 | 
						|
	retract(current_kbest(OldThres,List,Length)),
 | 
						|
	sorted_insert(NewLogProb-Cl,List,NewList),
 | 
						|
	NewLength is Length+1,
 | 
						|
	(NewLength < K ->
 | 
						|
	    assert(current_kbest(OldThres,NewList,NewLength))
 | 
						|
	;
 | 
						|
	(NewLength>K -> 
 | 
						|
	    First is NewLength-K+1,
 | 
						|
	    cutoff(NewList,NewLength,First,FinalList,FinalLength)
 | 
						|
	   ; FinalList=NewList, FinalLength=NewLength),
 | 
						|
	FinalList=[NewThres-_|_],
 | 
						|
	nb_setval(problog_threshold,NewThres),
 | 
						|
	assert(current_kbest(NewThres,FinalList,FinalLength))).
 | 
						|
 | 
						|
sorted_insert(A,[],[A]).
 | 
						|
sorted_insert(A-LA,[B1-LB1|B], [A-LA,B1-LB1|B] ) :-
 | 
						|
	A =< B1.
 | 
						|
sorted_insert(A-LA,[B1-LB1|B], [B1-LB1|C] ) :-
 | 
						|
	A > B1,
 | 
						|
	sorted_insert(A-LA,B,C).
 | 
						|
 | 
						|
% keeps all entries with lowest probability, even if implying a total of more than k
 | 
						|
cutoff(List,Len,1,List,Len) :- !.
 | 
						|
cutoff([P-L|List],Length,First,[P-L|List],Length) :-
 | 
						|
	nth(First,[P-L|List],PF-_),
 | 
						|
	PF=:=P,
 | 
						|
	!.
 | 
						|
cutoff([_|List],Length,First,NewList,NewLength) :-
 | 
						|
	NextFirst is First-1,
 | 
						|
	NextLength is Length-1,
 | 
						|
	cutoff(List,NextLength,NextFirst,NewList,NewLength).
 | 
						|
 | 
						|
build_prefixtree([]).
 | 
						|
build_prefixtree([_-[]|_List]) :-
 | 
						|
	!,
 | 
						|
	insert_ptree(true,1).
 | 
						|
build_prefixtree([_-L|List]) :-
 | 
						|
	insert_ptree(L,1),
 | 
						|
	build_prefixtree(List).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% exact probability 
 | 
						|
% problog_exact(+Goal,-Prob,-Status)
 | 
						|
%
 | 
						|
% using all proofs = using all proofs with probability > 0
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_exact(Goal,Prob,Status) :-
 | 
						|
	problog_low(Goal,0,Prob,Status).
 | 
						|
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
% probability by sampling: 
 | 
						|
% running another N samples until 95percentCI-width<Delta 
 | 
						|
% lazy sampling using three-valued array indexed by internal fact IDs
 | 
						|
%
 | 
						|
% still collects actual proofs found in samples in ptree, though this is no longer used  
 | 
						|
%   by method itself, only to write number to log-file
 | 
						|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 | 
						|
 | 
						|
problog_montecarlo(_,_,_) :-
 | 
						|
	non_ground_fact(_),
 | 
						|
	!,
 | 
						|
	format(user_error,'Current database contains non-ground facts.',[]),
 | 
						|
	format(user_error,'Monte Carlo inference is not possible in this case. Try k-best instead.',[]),
 | 
						|
	fail.
 | 
						|
	
 | 
						|
 | 
						|
problog_montecarlo(Goal,Delta,Prob) :-
 | 
						|
        nb_getval(probclause_counter,ID), !,
 | 
						|
        C is ID+1,
 | 
						|
        static_array(mc_sample,C,char),
 | 
						|
  	problog_control(off,up),
 | 
						|
	problog_flag(mc_batchsize,N),
 | 
						|
	problog_flag(mc_logfile,File1),
 | 
						|
	problog_flag(dir,Dir),
 | 
						|
	atomic_concat([Dir,File1],File),
 | 
						|
	montecarlo(Goal,Delta,N,File),
 | 
						|
	retract(mc_prob(Prob)).
 | 
						|
 | 
						|
montecarlo(Goal,Delta,K,File) :-
 | 
						|
        reset_static_array(mc_sample),
 | 
						|
	problog_control(on,mc),
 | 
						|
	open(File,write,Log),
 | 
						|
	format(Log,'# goal: ~q~n#delta: ~w~n',[Goal,Delta]),
 | 
						|
	format(Log,'# num_programs  prob   low   high  diff  time   cache_size  num_pos~2n',[]),
 | 
						|
	close(Log),
 | 
						|
	statistics(walltime,[T1,_]),
 | 
						|
	init_ptree(1),
 | 
						|
	(problog_flag(verbose,true) -> format('search for ~q~n',[Goal]);true),
 | 
						|
	montecarlo(Goal,Delta,K,0,File,0,T1),
 | 
						|
	problog_control(off,mc),
 | 
						|
	delete_ptree(1).
 | 
						|
 | 
						|
% calculate values after K samples
 | 
						|
montecarlo(Goal,Delta,K,SamplesSoFar,File,PositiveSoFar,InitialTime) :-
 | 
						|
	SamplesNew is SamplesSoFar+1,
 | 
						|
	SamplesNew mod K =:= 0,
 | 
						|
	!,
 | 
						|
	copy_term(Goal,GoalC),
 | 
						|
	(mc_prove(GoalC) -> Next is PositiveSoFar+1; Next=PositiveSoFar),
 | 
						|
	Prob is Next/SamplesNew, 
 | 
						|
	Epsilon is 2*sqrt(Prob*(1-Prob)/SamplesNew), 
 | 
						|
	Low is Prob-Epsilon,
 | 
						|
	High is Prob+Epsilon,
 | 
						|
	Diff is 2*Epsilon,
 | 
						|
	statistics(walltime,[T2,_]),
 | 
						|
	Time is (T2-InitialTime)/1000,
 | 
						|
	count_ptree(1,CacheSize),
 | 
						|
	(problog_flag(verbose,true) -> format('~n~w samples~nestimated probability ~w~n95 percent confidence interval [~w,~w]~n',[SamplesNew,Prob,Low,High]);true),
 | 
						|
	open(File,append,Log),
 | 
						|
	format(Log,'~w  ~8f  ~8f  ~8f  ~8f  ~3f  ~w  ~w~n',[SamplesNew,Prob,Low,High,Diff,Time,CacheSize,Next]),
 | 
						|
	close(Log),
 | 
						|
	((Diff<Delta; Diff =:= 0) -> 	(problog_flag(verbose,true) -> format('Runtime ~w sec~2n',[Time]);true),assert(mc_prob(Prob))
 | 
						|
		    ;	
 | 
						|
	                montecarlo(Goal,Delta,K,SamplesNew,File,Next,InitialTime)).
 | 
						|
 | 
						|
% continue until next K samples done
 | 
						|
montecarlo(Goal,Delta,K,SamplesSoFar,File,PositiveSoFar,InitialTime) :-
 | 
						|
	SamplesNew is SamplesSoFar+1,
 | 
						|
	copy_term(Goal,GoalC),
 | 
						|
	(mc_prove(GoalC) -> Next is PositiveSoFar+1; Next=PositiveSoFar),
 | 
						|
	montecarlo(Goal,Delta,K,SamplesNew,File,Next,InitialTime).
 | 
						|
 | 
						|
mc_prove(A) :- !,
 | 
						|
	(get_some_proof(A) ->
 | 
						|
	 clean_sample
 | 
						|
	; 
 | 
						|
	 clean_sample,fail
 | 
						|
	).	
 | 
						|
 | 
						|
clean_sample :-
 | 
						|
        reset_static_array(mc_sample),
 | 
						|
	fail.
 | 
						|
clean_sample.
 | 
						|
 | 
						|
% find new proof
 | 
						|
get_some_proof(Goal) :-
 | 
						|
	init_problog(0),
 | 
						|
	problog_call(Goal),
 | 
						|
	b_getval(problog_current_proof,Used),
 | 
						|
	(Used == [] -> Proof=true; reverse(Used,Proof)),
 | 
						|
	insert_ptree(Proof,1).
 | 
						|
 |