- the shift function is now defined and cpr_shift_fwd is proved

[helm.git] / matita / matita / contribs / lambda-delta / Basic-2 / grammar / term_weight.ma

diff --git a/matita/matita/contribs/lambda-delta/Basic-2/grammar/term_weight.ma b/matita/matita/contribs/lambda-delta/Basic-2/grammar/term_weight.ma
index 5d880eb6e09692491f93b15977f207b305b04d57..3e70635072fdfe55d4c7a40e588355ad74cdab59 100644 (file)
--- a/matita/matita/contribs/lambda-delta/Basic-2/grammar/term_weight.ma
+++ b/matita/matita/contribs/lambda-delta/Basic-2/grammar/term_weight.ma
@@ -14,9 +14,8 @@
 
 include "Basic-2/grammar/term.ma".
 
-(* WEIGHT *******************************************************************)
+(* WEIGHT OF A TERM *********************************************************)
 
-(* the weight of a term *)
 let rec tw T ≝ match T with
 [ TSort _     ⇒ 1
 | TLRef _     ⇒ 1
@@ -25,6 +24,8 @@ let rec tw T ≝ match T with
 
 interpretation "weight (term)" 'Weight T = (tw T).
 
-axiom tw_wf_ind: ∀P:term→Prop.
-                 (∀T2. (∀T1. # T1 < # T2 → P T1) → P T2) →
-                 ∀T. P T.
+(* Basic properties *********************************************************)
+
+axiom tw_wf_ind: ∀R:term→Prop.
+                 (∀T2. (∀T1. #[T1] < #[T2] → R T1) → R T2) →
+                 ∀T. R T.