Merge subinstances branch by me and Tom Prince.

This adds two experimental features to the typeclass implementation:
- Path cuts: a way to specify through regular expressions on instance names
search pathes that should be avoided (e.g. [proper_flip proper_flip]).
Regular expression matching is implemented through naïve derivatives.
- Forward hints for subclasses: e.g. [Equivalence -> Reflexive] is no
longer applied backwards, but introducing a specific [Equivalence] in the
environment register a [Reflexive] hint as well. Currently not
backwards-compatible, the next patch will allow to specify direction
of subclasses hints.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@14671 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 4 insertions, 2 deletions

diff --git a/theories/Numbers/Integer/Abstract/ZBits.v b/theories/Numbers/Integer/Abstract/ZBits.v
index 39e9f02c5..92afbcb53 100644
--- a/theories/Numbers/Integer/Abstract/ZBits.v
+++ b/theories/Numbers/Integer/Abstract/ZBits.v
@@ -51,6 +51,8 @@ Qed.
 Definition b2z (b:bool) := if b then 1 else 0.
 Local Coercion b2z : bool >-> t.
 
+Instance b2z_wd : Proper (Logic.eq ==> eq) b2z := _.
+
 Lemma exists_div2 a : exists a' (b:bool), a == 2*a' + b.
 Proof.
  elim (Even_or_Odd a); [intros (a',H)| intros (a',H)].
@@ -84,8 +86,8 @@ Qed.
 
 Lemma testbit_spec' a n : 0<=n -> a.[n] == (a / 2^n) mod 2.
 Proof.
- intro Hn. revert a. apply le_ind with (4:=Hn).
- solve_proper.
+ intro Hn. revert a. apply le_ind with (4:=Hn). 
+   solve_proper.
  intros a. nzsimpl.
  destruct (exists_div2 a) as (a' & b & H). rewrite H at 1.
  rewrite testbit_0_r. apply mod_unique with a'; trivial.