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author | Jason Gross <jgross@mit.edu> | 2017-06-27 12:55:34 -0400 |
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committer | Jason Gross <jgross@mit.edu> | 2017-06-30 13:21:10 -0400 |
commit | eb17292767bda59f9d9452da926ac57d5bc83ae4 (patch) | |
tree | 593f0e5904bc6b16a7cf71c6d313891cc73df455 /CHANGES | |
parent | 35e0f327405fb659c7ec5f9f7d26ea284aa45810 (diff) |
Update CHANGES with inversion_sigma entry
Diffstat (limited to 'CHANGES')
-rw-r--r-- | CHANGES | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -6,6 +6,17 @@ Tactics - New tactic "extensionality in H" which applies (possibly dependent) functional extensionality in H supposed to be a quantified equality until giving a bare equality. +- New tactic "inversion_sigma" which turns equalities of dependent + pairs (e.g., "existT P x p = existT P y q", frequently left over by + "inversion" on a dependent type family) into pairs of equalities + (e.g., a hypothesis "H : x = y" and a hypothesis of type "rew H in p + = q"); these hypotheses can subsequently be simplified using + "subst", without ever invoking any kind of axiom asserting + uniqueness of identity proofs. If you want to explicitly specify the + hypothesis to be inverted, or name the generated hypotheses, you can + invoke "induction H as [H1 H2] using eq_sigT_rect". The tactic also + works for "sig", "sigT2", and "sig2", and there are similar + "eq_sig*_rect" induction lemmas. - Tactic "specialize with ..." now accepts any partial bindings. Missing bindings are either solved by unification or left quantified in the hypothesis. |