update in delayd_updating

[helm.git] / matita / matita / contribs / lambdadelta / delayed_updating / reduction / dfr.ma

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
index 724168bdf800bc9ede762ee9f5493700704b30f9..27468022ad4c4e22109173830d80a04d6498f657 100644 (file)
--- a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/dfr.ma
@@ -12,20 +12,22 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "ground/xoa/ex_3_1.ma".
-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_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 FOCALIZED REDUCTION **********************************************)
+(* 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
-  "delayed focalized reduction (preterm)"
-  'BlackRightArrow t1 p q t2 = (dfr p q t1 t2).
+  "focused reduction with delayed updating (prototerm)"
+  'BlackRightArrowDF t1 r t2 = (dfr r t1 t2).