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yap-6.3/CHR/chr/examples/listdom.pl
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124 lines
3.6 KiB
Prolog

% Slim Abdennadher, Thom Fruehwirth, LMU, July 1998
% Finite (enumeration, list) domain solver over integers
:- use_module( library(chr)).
:- use_module( library(lists),
[member/2,memberchk/2,select/3,
last/2,is_list/1,min_list/2, max_list/2,
remove_duplicates/2]).
handler listdom.
option(debug_compile,on).
option(already_in_heads, on).
option(check_guard_bindings, off).
% for domain constraints
operator( 700,xfx,'::').
operator( 600,xfx,'..').
% for inequality constraints
operator( 700,xfx,lt).
operator( 700,xfx,le).
operator( 700,xfx,ne).
constraints (::)/2, le/2, lt/2, ne/2, add/3, mult/3.
% X::Dom - X must be element of the finite list domain Dom
% special cases
X::[] <=> fail.
%X::[Y] <=> X=Y.
%X::[A|L] <=> ground(X) | (member(X,[A|L]) -> true).
% intersection of domains for the same variable
X::L1, X::L2 <=> is_list(L1), is_list(L2) |
intersection(L1,L2,L) , X::L.
X::L, X::Min..Max <=> is_list(L) |
remove_lower(Min,L,L1), remove_higher(Max,L1,L2),
X::L2.
% interaction with inequalities
X le Y, X::L1, Y::L2 ==> is_list(L1),is_list(L2),
min_list(L1,MinX), min_list(L2,MinY), MinX > MinY |
max_list(L2,MaxY), Y::MinX..MaxY.
X le Y, X::L1, Y::L2 ==> is_list(L1),is_list(L2),
max_list(L1,MaxX), max_list(L2,MaxY), MaxX > MaxY |
min_list(L1,MinX), X::MinX..MaxY.
X lt Y, X::L1, Y::L2 ==> is_list(L1), is_list(L2),
max_list(L1,MaxX), max_list(L2,MaxY),
MaxY1 is MaxY - 1, MaxY1 < MaxX |
min_list(L1,MinX), X::MinX..MaxY1.
X lt Y, X::L1, Y::L2 ==> is_list(L1), is_list(L2),
min_list(L1,MinX), min_list(L2,MinY),
MinX1 is MinX + 1, MinX1 > MinY |
max_list(L2,MaxY), Y :: MinX1..MaxY.
X ne Y \ Y::D <=> ground(X), is_list(D), member(X,D) | select(X,D,D1), Y::D1.
Y ne X \ Y::D <=> ground(X), is_list(D), member(X,D) | select(X,D,D1), Y::D1.
Y::D \ X ne Y <=> ground(X), is_list(D), \+ member(X,D) | true.
Y::D \ Y ne X <=> ground(X), is_list(D), \+ member(X,D) | true.
% interaction with addition
% no backpropagation yet!
add(X,Y,Z), X::L1, Y::L2 ==> is_list(L1), is_list(L2) |
all_addition(L1,L2,L3), Z::L3.
% interaction with multiplication
% no backpropagation yet!
mult(X,Y,Z), X::L1, Y::L2 ==> is_list(L1), is_list(L2) |
all_multiplication(L1,L2,L3), Z::L3.
% auxiliary predicates =============================================
remove_lower(_,[],L1):- !, L1=[].
remove_lower(Min,[X|L],L1):-
X@<Min,
!,
remove_lower(Min,L,L1).
remove_lower(Min,[X|L],[X|L1]):-
remove_lower(Min,L,L1).
remove_higher(_,[],L1):- !, L1=[].
remove_higher(Max,[X|L],L1):-
X@>Max,
!,
remove_higher(Max,L,L1).
remove_higher(Max,[X|L],[X|L1]):-
remove_higher(Max,L,L1).
intersection([], _, []).
intersection([Head|L1tail], L2, L3) :-
memberchk(Head, L2),
!,
L3 = [Head|L3tail],
intersection(L1tail, L2, L3tail).
intersection([_|L1tail], L2, L3) :-
intersection(L1tail, L2, L3).
all_addition(L1,L2,L3) :-
setof(Z, X^Y^(member(X,L1), member(Y,L2), Z is X + Y), L3).
all_multiplication(L1,L2,L3) :-
setof(Z, X^Y^(member(X,L1), member(Y,L2), Z is X * Y), L3).
% EXAMPLE ==========================================================
/*
?- X::[1,2,3,4,5,6,7], Y::[2,4,6,7,8,0], Y lt X, X::4..9, X ne Y,
add(X,Y,Z), mult(X,Y,Z).
*/
% end of handler listdom.pl =================================================
% ===========================================================================