X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fdelayed_updating%2Freduction%2Fdfr.ma;h=5b5036593713ac1c84f09b2b7b6649f3aebd834a;hb=2cc4eb5d0210be58286e028278852122dcb68052;hp=ed077ae2cc772df22b7227dab1750ace5c243afd;hpb=513a56a5990201abcf038e7242779e2d73621c86;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
index ed077ae2c..5b5036593 100644
--- a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
@@ -16,15 +16,17 @@ include "delayed_updating/syntax/path_depth.ma".
 include "delayed_updating/syntax/path_structure.ma".
 include "delayed_updating/syntax/path_balanced.ma".
 include "delayed_updating/syntax/prototerm_constructors.ma".
+include "delayed_updating/syntax/prototerm_equivalence.ma".
 include "delayed_updating/substitution/fsubst.ma".
 include "delayed_updating/notation/relations/black_rightarrow_df_4.ma".
 
 (* DELAYED FOCUSED REDUCTION ************************************************)
 
-inductive dfr (p) (q) (t): predicate prototerm ≝
-| dfr_beta (b):
-  let r ≝ p●𝗔◗b●𝗟◗q in
-  r◖𝗱(↑❘q❘) ϵ t → ⊓(⊗b) → dfr p q t (t[⋔r←𝛗(↑❘q❘).t⋔(p◖𝗦)])
+definition dfr (p) (q): relation2 prototerm prototerm ≝
+           λt1,t2. ∃b.
+           let r ≝ p●𝗔◗b●𝗟◗q in
+           ∧∧ ⊓(⊗b) & r◖𝗱(↑❘q❘) ϵ t1 &
+              t2 ⇔ t1[⋔r←𝛗(↑❘q❘).t1⋔(p◖𝗦)]
 .
 
 interpretation