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view rstd.pl @ 0:b35e4dc6ec23
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author | kono |
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date | Sat, 16 Sep 1995 12:20:45 +0900 |
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children | 683efd6f9a81 |
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% /* Copyright (C) 1991, Shinji Kono, Sony Computer Science Laboratory, Inc. The University, Newcastle upton Tyne Everyone is permitted to copy and distribute verbatim copies of this license, but changing it is not allowed. You can also use this wording to make the terms for other programs. send your comments to kono@csl.sony.co.jp $Id$ */ % ITL subterm standarization with BDT % % Fri Jun 21 10:32:58 BST 1991 % % a standard form of ITL, based on subterm classification % % subterm_init :- abolish(sb,2), asserta((sb([],-1))), abolish(sbn,1), asserta(sbn(0)). std_check(I,J) :- sb(I,J),!. std_check(I,N1) :- retract(sbn(N)),N1 is N+1,asserta(sbn(N1)), assertz(sb(I,N1)),!. itlstd(P,List) :- sbdt(P,List,(0,[]),_). itlstd(P,List,S) :- sbdt(P,List,(0,S),_). % BDT classification of subterm sbdt(true,true,L,L):-!. sbdt(false,false,L,L):-!. sbdt(P,F,L,L) :- atomic(P),!,F= ?(P,true,false). sbdt(?(C,T,F),?(C,T,F),L,L) :- !. sbdt(not(P),F,L,L1) :- !,sbdt(P,F0,L,L0),sbdt_not(F0,F,L0,L1),!. sbdt_not(true,false,L,L). sbdt_not(false,true,L,L). sbdt_not(F,?(H,A1,B1),L,L1):- arg(1,F,H),arg(2,F,A),arg(3,F,B), sbdt_not(A,A1,L,L0),sbdt_not(B,B1,L0,L1). sbdt((P,Q),F,L,L2) :- !, sbdt(P,P0,L,L0),sbdt(Q,Q0,L0,L1), sbdt_and(P0,Q0,F,L1,L2),!. sbdt_and(false,_,false,L,L):-!. sbdt_and(_,false,false,L,L):-!. sbdt_and(true,T,T,L,L):-!. sbdt_and(T,true,T,L,L):-!. sbdt_and(P,Q,R,L,L1) :-!, arg(1,P,PF),arg(1,Q,QF), sbdt_and(PF,QF,P,Q,R,L,L1). sbdt_and(PF,QF,P,Q,R,L,L1):-PF @< QF,!, sbdt_and(QF,PF,Q,P,R,L,L1). sbdt_and(PF,QF,P,Q,?(QF,R0,R1),L,L1):-PF @> QF,!, arg(2,Q,Q0),arg(3,Q,Q1), sbdt_and(Q0,P,R0,L,L0), sbdt_and(Q1,P,R1,L0,L1). sbdt_and(PF,PF,P,Q,?(PF,R0,R1),L,L1):- arg(2,P,P0),arg(3,P,P1), arg(2,Q,Q0),arg(3,Q,Q1), sbdt_and(P0,Q0,R0,L,L0), sbdt_and(P1,Q1,R1,L0,L1). sbdt((P;Q),F,L,L2) :- !, sbdt(P,P0,L,L0),sbdt(Q,Q0,L0,L1), sbdt_or(P0,Q0,F,L1,L2),!. sbdt_or(true,_,true,L,L):-!. sbdt_or(_,true,true,L,L):-!. sbdt_or(false,T,T,L,L):-!. sbdt_or(T,false,T,L,L):-!. sbdt_or(P,Q,R,L,L1) :-!, arg(1,P,PF),arg(1,Q,QF), sbdt_or(PF,QF,P,Q,R,L,L1). sbdt_or(PF,QF,P,Q,R,L,L1):-PF @< QF,!, sbdt_or(QF,PF,Q,P,R,L,L1). sbdt_or(PF,QF,P,Q,?(QF,R0,R1),L,L1):-PF @> QF,!, arg(2,Q,Q0),arg(3,Q,Q1), sbdt_or(Q0,P,R0,L,L0), sbdt_or(Q1,P,R1,L0,L1). sbdt_or(PF,PF,P,Q,?(PF,R0,R1),L,L1):- arg(2,P,P0),arg(3,P,P1), arg(2,Q,Q0),arg(3,Q,Q1), sbdt_or(P0,Q0,R0,L,L0), sbdt_or(P1,Q1,R1,L0,L1). sbdt((P&Q), ?(N,true,false),L,L1) :-!, sbdt(P,P1,L,L0),sbdt(Q,Q1,L0,L1), % projection touch later part of chop std_check((P1&Q1),N). % bottom up development is effective for quantifier sbdt(exists(P,Q), ?(N,true,false),L,L1) :-!, sbdt(Q,QF,L,L1), std_check(exists(P,QF),N). sbdt(proj(P,Q), ?(N,true,false),L,L1) :-!, sbdt(Q,QF,L,L1), % P part is fixed std_check(proj(P,QF),N). sbdt(prefix(P), ?(N,true,false),L,L1) :-!, sbdt(P,PF,L,L1), % P part is fixed std_check(prefix(PF),N). %sbdt(^(R), ?(N,true,false),(I,L),(I1,L1)) :-!, % recorded(current,S,_),!, % regular_check(L,L1,S,R,I,I1,N). sbdt(^(R), ?(N,true,false),(I,L),(I,L)) :-!, std_check(^(R),N). % remove singleton regular variable sbdt(^(R,S), F,(I,L),(I,L)) :- member((^(R,S),F),L),!. sbdt(^(R,S), ?(N,true,false),(I,L),(I,L)) :-!, std_check(^(R,S),N). % Simple Functor sbdt(Func,F,L,L) :- functor(Func,_,1),!,F= ?(N,true,false), std_check(Func,N). sbdt(Func,F,L,L) :- functor(Func,_,2),!,F= ?(N,true,false), std_check(Func,N). sbdt(Def,true,L,L) :- write('bdtstd error: '),write(Def),nl. % renumbering (not used now) regular_check([],[S,I1],S,R,I,I1,N) :- !, I1 is I+1, std_check(^(R,I1),N). regular_check([S,J|L],L,S,R,I,I1,N) :- !, I1=I, std_check(^(R,J),N). regular_check([_,_|L1],L,S,R,I,I1,N) :- !, regular_check(L1,L,S,R,I,I1,N). sbterm :- listing(sb/2),listing(itl_state/2). bdt2itl(B,F) :- number(B),!,sb(F0,B), bdt2itl(F0,F). bdt2itl(^(R,N),^(R,N)) :-!. bdt2itl(st(R),st(R)) :-!. bdt2itl(?(IF,THEN,ELSE),F) :- bdt2itl(IF,IF0),bdt2itl(THEN,THEN0),bdt2itl(ELSE,ELSE0), bdt2itl_opt(IF0,THEN0,ELSE0,F). % little more readable representation bdt2itl_opt(IF,true,false,IF) :- !. bdt2itl_opt(IF,false,true,not(IF)) :- !. bdt2itl_opt(IF,true,ELSE,(IF;ELSE)) :- !. bdt2itl_opt(IF,THEN,false,(IF,THEN)) :- !. bdt2itl_opt(IF,false,ELSE,(not(IF);ELSE)) :- !. bdt2itl_opt(IF,THEN,true,(not(IF),THEN)) :- !. bdt2itl_opt(IF,THEN,ELSE,?(IF,THEN,ELSE)) :- !. bdt2itl(B,F) :- atom(B),!,F=B. bdt2itl(B,F) :- functor(B,H,N),functor(F,H,N),bdt2itl_subterm(N,N,B,F). bdt2itl_subterm(0,_,_,_) :- !. bdt2itl_subterm(N,N1,F,F0) :- N0 is N-1, arg(N,F,A),arg(N,F0,A0), bdt2itl(A,A0),bdt2itl_subterm(N0,N1,F,F0). % BDT end %