update in delayed_updating

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

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/ifr.ma b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/ifr.ma
index d087bdbb736fd4aea41de56ae86ef8e249a5f1cd..582f6ed5761ff450a54d34d6b113c5c07e9aaaa1 100644 (file)
--- a/matita/matita/contribs/lambdadelta/delayed_updating/reduction/ifr.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/reduction/ifr.ma
@@ -21,10 +21,11 @@ include "delayed_updating/notation/relations/black_rightarrow_f_4.ma".
 
 (* IMMEDIATE FOCUSED REDUCTION ************************************************)
 
-inductive ifr (p) (q) (t): predicate prototerm ≝
-| ifr_beta (b):
-  let r ≝ p●𝗔◗b●𝗟◗q in
-  r◖𝗱(↑❘q❘) ϵ t → ⊓(⊗b) → ifr p q t (t[⋔r←↑[𝐮❨↑❘q❘❩]t⋔(p◖𝗦)])
+definition ifr (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←↑[𝐮❨↑❘q❘❩]t1⋔(p◖𝗦)]
 .
 
 interpretation