921e576877
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1138 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
99 lines
2.7 KiB
Plaintext
99 lines
2.7 KiB
Plaintext
=================================================================
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Logtalk - Object oriented extension to Prolog
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Release 2.21.0
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Copyright (c) 1998-2004 Paulo Moura. All Rights Reserved.
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=================================================================
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% start by loading the example:
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| ?- logtalk_load(loader).
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...
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% translate a single logic proposition:
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| ?- translator::translate((p v ~q) => (r & k), Cs).
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r :- p.
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k :- p.
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q; r :- .
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q; k :- .
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Cs = [cl([r],[p]),cl([k],[p]),cl([q,r],[]),cl([q,k],[])]
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yes
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% translate a single logic proposition printing each translation step:
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| ?- translator::step_by_step((p v ~q) => (r & k), Cs).
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Processing proposition: p v ~q=>r&k
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1. Remove implications: ~ (p v ~q) v r&k
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2. Distribute negation: ~p&q v r&k
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3. Remove existential quantifiers: ~p&q v r&k
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4. Convert to prenex normal form: ~p&q v r&k
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5. Remove universal quantifiers: ~p&q v r&k
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6. Convert to conjunctive normal form: (~p v r)&(~p v k)&((q v r)&(q v k))
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7. Convert to clauses: [cl([r],[p]),cl([k],[p]),cl([q,r],[]),cl([q,k],[])]
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Clauses in Prolog-like notation:
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r :- p.
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k :- p.
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q; r :- .
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q; k :- .
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Cs = [cl([r],[p]),cl([k],[p]),cl([q,r],[]),cl([q,k],[])]
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yes
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% translate a single logic proposition printing each translation step:
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| ?- translator::step_by_step(all(X, exists(Y, p(X) v ~q(X) => r(X, Y))), Cs).
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Processing proposition: all(X, exists(Y, p(X)v~q(X)=>r(X, Y)))
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1. Remove implications: all(X, exists(Y, ~ (p(X)v~q(X))v r(X, Y)))
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2. Distribute negation: all(X, exists(Y, ~p(X)&q(X)v r(X, Y)))
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3. Remove existential quantifiers: all(X, ~p(X)&q(X)v r(X, f1(X)))
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4. Convert to prenex normal form: all(X, ~p(X)&q(X)v r(X, f1(X)))
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5. Remove universal quantifiers: ~p(X)&q(X)v r(X, f1(X))
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6. Convert to conjunctive normal form: (~p(X)v r(X, f1(X)))& (q(X)v r(X, f1(X)))
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7. Convert to clauses: [cl([r(X, f1(X))], [p(X)]), cl([q(X), r(X, f1(X))], [])]
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Clauses in Prolog-like notation:
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r(X, f1(X)) :- p(X).
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q(X); r(X, f1(X)) :- .
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X = X
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Y = f1(X)
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Cs = [cl([r(X, f1(X))], [p(X)]), cl([q(X), r(X, f1(X))], [])]
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yes
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% translate a single logic proposition printing each translation step:
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| ?- translator::step_by_step(all(X, men(X) => mortal(X)), Cs).
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Processing proposition: all(X, men(X)=>mortal(X))
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1. Remove implications: all(X, ~men(X)v mortal(X))
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2. Distribute negation: all(X, ~men(X)v mortal(X))
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3. Remove existential quantifiers: all(X, ~men(X)v mortal(X))
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4. Convert to prenex normal form: all(X, ~men(X)v mortal(X))
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5. Remove universal quantifiers: ~men(X)v mortal(X)
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6. Convert to conjunctive normal form: ~men(X)v mortal(X)
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7. Convert to clauses: [cl([mortal(X)], [men(X)])]
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Clauses in Prolog-like notation:
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mortal(X) :- men(X).
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X = X
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Cs = [cl([mortal(X)], [men(X)])]
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yes
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