eb05d95935
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1162 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
114 lines
2.1 KiB
Plaintext
114 lines
2.1 KiB
Plaintext
=================================================================
|
|
Logtalk - Object oriented extension to Prolog
|
|
Release 2.21.2
|
|
|
|
Copyright (c) 1998-2004 Paulo Moura. All Rights Reserved.
|
|
=================================================================
|
|
|
|
|
|
% start by loading the example:
|
|
|
|
| ?- logtalk_load(loader).
|
|
...
|
|
|
|
|
|
% solver - a simple meta-interpreter for pure Prolog:
|
|
|
|
| ?- solver::assertz(member_of(H, [H| _])).
|
|
|
|
H = _G178
|
|
yes
|
|
|
|
| ?- solver::assertz((member_of(H, [_| T]) :- member_of(H, T))).
|
|
|
|
H = _G181
|
|
T = _G179
|
|
yes
|
|
|
|
| ?- solver::solve(member_of(2, [1,2,3])).
|
|
|
|
yes
|
|
|
|
| ?- solver::solve(member_of(X, [1,2,3])).
|
|
|
|
X = 1 ;
|
|
X = 2 ;
|
|
X = 3
|
|
yes
|
|
|
|
|
|
% proof_tree - a simple meta-interpreter for pure Prolog that
|
|
% construct a proof tree:
|
|
|
|
| ?- proof_tree::assertz(member_of(H, [H| _])).
|
|
|
|
H = _G178
|
|
yes
|
|
|
|
| ?- proof_tree::assertz((member_of(H, [_| T]) :- member_of(H, T))).
|
|
|
|
H = _G181
|
|
T = _G179
|
|
yes
|
|
|
|
| ?- proof_tree::solve(member_of(2, [1,2,3]), Tree).
|
|
|
|
Tree = member_of(2, [1, 2, 3]):- (member_of(2, [2, 3]):-true)
|
|
yes
|
|
|
|
|
|
% tracer - a simple meta-interpreter for tracing goal proofs
|
|
% using pure Prolog:
|
|
|
|
|
|
| ?- tracer::assertz(member_of(H, [H| _])).
|
|
|
|
H = _G178
|
|
yes
|
|
|
|
| ?- tracer::assertz((member_of(H, [_| T]) :- member_of(H, T))).
|
|
|
|
H = _G181
|
|
T = _G179
|
|
yes
|
|
|
|
| ?- tracer::trace(member_of(3, [1,2,3])).
|
|
|
|
1 call: member_of(3, [1, 2, 3])
|
|
2 call: member_of(3, [2, 3])
|
|
3 call: member_of(3, [3])
|
|
3 exit: member_of(3, [3])
|
|
2 exit: member_of(3, [2, 3])
|
|
1 exit: member_of(3, [1, 2, 3])
|
|
yes
|
|
|
|
| ?- tracer::trace(member_of(X, [1,2,3])).
|
|
|
|
1 call: member_of(_G187, [1, 2, 3])
|
|
1 exit: member_of(1, [1, 2, 3])
|
|
|
|
X = 1 ;
|
|
1 redo: member_of(1, [1, 2, 3])
|
|
2 call: member_of(_G187, [2, 3])
|
|
2 exit: member_of(2, [2, 3])
|
|
1 exit: member_of(2, [1, 2, 3])
|
|
|
|
X = 2 ;
|
|
1 redo: member_of(2, [1, 2, 3])
|
|
2 redo: member_of(2, [2, 3])
|
|
3 call: member_of(_G187, [3])
|
|
3 exit: member_of(3, [3])
|
|
2 exit: member_of(3, [2, 3])
|
|
1 exit: member_of(3, [1, 2, 3])
|
|
|
|
X = 3 ;
|
|
1 redo: member_of(3, [1, 2, 3])
|
|
2 redo: member_of(3, [2, 3])
|
|
3 redo: member_of(3, [3])
|
|
4 call: member_of(_G187, [])
|
|
4 fail: member_of(_G187, [])
|
|
3 fail: member_of(_G187, [3])
|
|
2 fail: member_of(_G187, [2, 3])
|
|
1 fail: member_of(_G187, [1, 2, 3])
|
|
no
|