Propagated information from the reduction tactics to the kernel so

that the kernel conversion solves the delta/delta critical pair the
same way the tactics did. This allows to improve Qed time when slow
down is due to conversion having (arbitrarily) made the wrong choice.
Propagation is done thanks to a new kind of cast called REVERTcast.

Notes:
- Vm conversion not modified
- size of vo generally grows because of additional casts
- this remains a heuristic... for the record, when a reduction tactic
  is applied on the goal t leading to new goal t', this is translated
  in the kernel in a conversion t' <= t where, hence, reducing in t'
  must be preferred; what the propagation of reduction cast to the
  kernel does not do is whether it is preferable to first unfold c or
  to first compare u' and u in "c u' = c u"; in particular,
  intermediate casts are sometimes useful to solve this kind of issues
  (this is the case e.g. in Nijmegen/LinAlg/subspace_dim.v where the
  combination "simpl;red" needs the intermediate cast to ensure Qed
  answers quickly); henceforth the merge of nested casts in mkCast is
  deactivated
- for tactic "change", REVERTcast should be used when conversion is in
  the hypotheses, but convert_hyp does not (yet) support this (would
  require e.g. that convert_hyp overwrite some given hyp id with a
  body-cleared let-binding new_id := Cast(old_id,REVERTCast,t))

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@14407 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/conv_oracle.mli b/kernel/conv_oracle.mli
index a41b02f0c..09ca4b92b 100644
--- a/kernel/conv_oracle.mli
+++ b/kernel/conv_oracle.mli
@@ -12,7 +12,7 @@ open Names
    If [oracle_order kn1 kn2] is true, then unfold kn1 first.
    Note: the oracle does not introduce incompleteness, it only
    tries to postpone unfolding of "opaque" constants. *)
-val oracle_order : 'a tableKey -> 'a tableKey -> bool
+val oracle_order : bool -> 'a tableKey -> 'a tableKey -> bool
 
 (** Priority for the expansion of constant in the conversion test.
  * Higher levels means that the expansion is less prioritary.