diff options
Diffstat (limited to 'src/proof/alethe/alethe_post_processor.cpp')
| -rw-r--r-- | src/proof/alethe/alethe_post_processor.cpp | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/proof/alethe/alethe_post_processor.cpp b/src/proof/alethe/alethe_post_processor.cpp index 167b885f4..dd2927ead 100644 --- a/src/proof/alethe/alethe_post_processor.cpp +++ b/src/proof/alethe/alethe_post_processor.cpp @@ -909,6 +909,28 @@ bool AletheProofPostprocessCallback::update(Node res, {}, *cdp); } + // ======== Double negation elimination + // See proof_rule.h for documentation on the NOT_NOT_ELIM rule. This comment + // uses variable names as introduced there. + // + // ---------------------------------- NOT_NOT + // (VP1:(cl (not (not (not F))) F)) (P:(not (not F))) + // ------------------------------------------------------------- RESOLUTION + // (cl F)* + // + // * the corresponding proof node is F + case PfRule::NOT_NOT_ELIM: + { + Node vp1 = nm->mkNode(kind::SEXPR, d_cl, children[0].notNode(), res); + + return addAletheStep(AletheRule::NOT_NOT, vp1, vp1, {}, {}, *cdp) + && addAletheStep(AletheRule::RESOLUTION, + res, + nm->mkNode(kind::SEXPR, d_cl, res), + {vp1, children[0]}, + {}, + *cdp); + } default: { return addAletheStep(AletheRule::UNDEFINED, |