mirror of
https://github.com/Mercury-Language/mercury.git
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e6c245092a
compiler/parse_goal.m:
Fix typo: A <= B was parsed as B => B.
tests/hard_coded/Mmakefile:
tests/hard_coded/implication.exp:
tests/hard_coded/implication.m:
Add test case.
NEWS:
Announce change.
102 lines
1.6 KiB
Mathematica
102 lines
1.6 KiB
Mathematica
%---------------------------------------------------------------------------%
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% vim: ts=4 sw=4 et ft=mercury
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%---------------------------------------------------------------------------%
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:- module implication.
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:- interface.
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:- import_module io.
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:- pred main(io::di, io::uo) is det.
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%---------------------------------------------------------------------------%
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:- implementation.
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main(!IO) :-
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io.write_string("implication:\n", !IO),
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( if t => t then
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ok(!IO)
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else
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bad(!IO)
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),
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( if t => f then
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bad(!IO)
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else
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ok(!IO)
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),
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( if f => t then
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ok(!IO)
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else
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bad(!IO)
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),
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( if f => f then
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ok(!IO)
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else
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bad(!IO)
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),
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io.write_string("reverse implication:\n", !IO),
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( if t <= t then
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ok(!IO)
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else
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bad(!IO)
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),
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( if f <= t then
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bad(!IO)
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else
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ok(!IO)
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),
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( if t <= f then
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ok(!IO)
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else
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bad(!IO)
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),
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( if f <= f then
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ok(!IO)
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else
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bad(!IO)
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),
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io.write_string("logical equivalence:\n", !IO),
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( if t <=> t then
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ok(!IO)
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else
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bad(!IO)
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),
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( if t <=> f then
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bad(!IO)
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else
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ok(!IO)
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),
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( if f <=> t then
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bad(!IO)
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else
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ok(!IO)
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),
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( if f <=> f then
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ok(!IO)
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else
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bad(!IO)
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),
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io.write_string("done.\n", !IO).
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:- pred t is semidet.
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t :- semidet_true.
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:- pred f is semidet.
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f :- semidet_false.
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:- pred ok(io::di, io::uo) is det.
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ok(!IO) :-
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io.write_string("ok\n", !IO).
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:- pred bad(io::di, io::uo) is det.
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bad(!IO) :-
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io.write_string("fail\n", !IO).
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