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6 commits

Author SHA1 Message Date
Leonardo de Moura
e3dc552c39 fix(library/simplifier): nontermination
The example tests/lua/simp1.lua demonstrates the issue.
The higher-order matcher matches closed terms that are definitionally equal.
So, given a definition

    definition a := 1

it will match 'a' with '1' since they are definitionally equal.

Then, if we have a theorem

    theorem a_eq_1 : a = 1

as a rewrite rule, it was triggering the following infinite loop when simplifying the expression "a"

   a --> 1 --> 1 --> 1 ...

The first simplification is expected. The other ones are not.
The problem is that "1" is definitionally equal to "a", and they match.
The rewrite_rule_set manager accepts the rule a --> 1 since the left-hand-side does not occur in the right-hand-side.

To avoid this loop, we test if the new expression is not equal to the previous one.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-31 15:55:21 -08:00
Leonardo de Moura
bbf6e6a256 feat(builtin/kernel): create default rule set in the kernel, and adjust unit tests
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-19 11:24:20 -08:00
Leonardo de Moura
7492fd5a2c feat(library/simplifier): add support for simplification by evaluation
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-19 10:34:55 -08:00
Leonardo de Moura
39c3b17eb7 feat(library/simplifier): add support for Eta-reduction in the simplifier
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-19 00:40:35 -08:00
Leonardo de Moura
ed009f4c88 feat(kernel/simplifier): add support for Beta-reduction in the simplifier
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-19 00:40:20 -08:00
Leonardo de Moura
32c5bc25e3 refactor(library/simplifier): cleanup rewrite_rule_set, and use it in the simplifier
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-18 20:52:33 -08:00