X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=components%2Ftactics%2FreductionTactics.ml;h=9c39caa6f4cee2a4f03fbf505591398a65c24fda;hb=b0a6c05decc9f0e731f70cfc5ae5350ae4046b79;hp=754b2c0c5b49cca403f94a8e3bde1ee86f2c9798;hpb=e00d05ab58597620345c2fd49b84a23efa8db34c;p=helm.git

diff --git a/components/tactics/reductionTactics.ml b/components/tactics/reductionTactics.ml
index 754b2c0c5..9c39caa6f 100644
--- a/components/tactics/reductionTactics.ml
+++ b/components/tactics/reductionTactics.ml
@@ -30,7 +30,7 @@ open ProofEngineTypes
 (* Note: this code is almost identical to change_tac and
 *  it could be unified by making the change function a callback *)
 let reduction_tac ~reduction ~pattern (proof,goal) =
-  let curi,metasenv,pbo,pty, attrs = proof in
+  let curi,metasenv,_subst,pbo,pty, attrs = proof in
   let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
   let change subst where terms metasenv ugraph =
    if terms = [] then where, metasenv, ugraph
@@ -88,7 +88,7 @@ let reduction_tac ~reduction ~pattern (proof,goal) =
       | _ as t -> t
     ) metasenv
   in
-  (curi,metasenv',pbo,pty, attrs), [metano]
+  (curi,metasenv',_subst,pbo,pty, attrs), [metano]
 ;;
 
 let simpl_tac ~pattern =
@@ -118,6 +118,12 @@ let normalize_tac ~pattern =
  mk_tactic (reduction_tac
   ~reduction:(const_lazy_reduction CicReduction.normalize) ~pattern)
 
+let head_beta_reduce_tac ?delta ?upto ~pattern =
+ mk_tactic (reduction_tac
+  ~reduction:
+    (const_lazy_reduction
+      (fun _context -> CicReduction.head_beta_reduce ?delta ?upto)) ~pattern)
+
 exception NotConvertible
 
 (* Note: this code is almost identical to reduction_tac and
@@ -129,9 +135,9 @@ exception NotConvertible
         reference variables that are local to the term that is going to be
         replaced. To fix this we should parse with_what in the context of the
         term(s) to be replaced. *)
-let change_tac ~pattern with_what  =
+let change_tac ?(with_cast=false) ~pattern with_what  =
  let change_tac ~pattern ~with_what (proof, goal) =
-  let curi,metasenv,pbo,pty, attrs = proof in
+  let curi,metasenv,_subst,pbo,pty, attrs = proof in
   let (metano,context,ty) as conjecture = CicUtil.lookup_meta goal metasenv in
   let change subst where terms metasenv ugraph =
    if terms = [] then where, metasenv, ugraph
@@ -200,7 +206,19 @@ let change_tac ~pattern with_what  =
         | _ as t -> t)
       metasenv
   in
-  (curi,metasenv',pbo,pty, attrs), [metano]
+   let proof,goal = (curi,metasenv',_subst,pbo,pty, attrs), metano in
+    if with_cast then
+     let metano' = ProofEngineHelpers.new_meta_of_proof ~proof in
+     let (newproof,_) =
+       let irl= CicMkImplicit.identity_relocation_list_for_metavariable context'
+       in
+        ProofEngineHelpers.subst_meta_in_proof
+         proof metano
+          (Cic.Cast (Cic.Meta(metano',irl),ty')) [metano',context',ty']
+     in
+      newproof, [metano']
+    else
+     proof,[goal]
   in
     mk_tactic (change_tac ~pattern ~with_what)