X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fdelayed_updating%2Freduction%2Fdfr.ma;h=27468022ad4c4e22109173830d80a04d6498f657;hb=829e3a8af3229c4e625245f7265dd67939da98c4;hp=8c84de0f240f66c3e61aed0d5fa2a35d81eeaf88;hpb=8db3579bec4d9a97af526f95a179587a2fbfe3e3;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 8c84de0f2..27468022a 100644
--- a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
@@ -12,19 +12,22 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "delayed_updating/syntax/path_structure.ma".
-include "delayed_updating/syntax/path_balanced.ma".
 include "delayed_updating/substitution/fsubst.ma".
-include "delayed_updating/notation/relations/black_rightarrow_df_4.ma".
+include "delayed_updating/syntax/prototerm_constructors.ma".
+include "delayed_updating/syntax/prototerm_eq.ma".
+include "delayed_updating/syntax/path_closed.ma".
+include "delayed_updating/notation/relations/black_rightarrow_df_3.ma".
+include "ground/xoa/ex_4_3.ma".
 
 (* DELAYED FOCUSED REDUCTION ************************************************)
 
-inductive dfr (p) (q) (t): predicate preterm ≝
-| dfr_beta (b) (n):
-  let r ≝ p●𝗔◗b●𝗟◗q◖𝗱❨n❩ in
-  r ϵ t → ⊓⊗b → dfr p q t (t[⋔r←t⋔(p◖𝗦)])
+definition dfr (r): relation2 prototerm prototerm ≝
+           λt1,t2.
+           ∃∃p,q,n. p●𝗔◗𝗟◗q = r &
+           q ϵ 𝐂❨n❩ & r◖𝗱↑n ϵ t1 &
+           t1[⋔r←𝛕↑n.(t1⋔(p◖𝗦))] ⇔ t2
 .
 
 interpretation
-  "focused balanced reduction with delayed updating (preterm)"
-  'BlackRightArrowDF t1 p q t2 = (dfr p q t1 t2).
+  "focused reduction with delayed updating (prototerm)"
+  'BlackRightArrowDF t1 r t2 = (dfr r t1 t2).