]> matita.cs.unibo.it Git - helm.git/blobdiff - matita/matita/contribs/lambdadelta/static_2/syntax/term_weight.ma
partial update in static_2
[helm.git] / matita / matita / contribs / lambdadelta / static_2 / syntax / term_weight.ma
index bcb826bb41bf7477067c229b2116c9d48105f31a..5b7853c572cac973b5a104e21e3a03be8766bdd4 100644 (file)
 (*                                                                        *)
 (**************************************************************************)
 
+include "ground/arith/pnat_lt_plus.ma".
 include "static_2/notation/functions/weight_1.ma".
 include "static_2/syntax/term.ma".
 
 (* WEIGHT OF A TERM *********************************************************)
 
 rec definition tw T ≝ match T with
-[ TAtom _     ⇒ 1
+[ TAtom _     ⇒ 𝟏
 | TPair _ V T ⇒ ↑(tw V + tw T)
 ].
 
@@ -26,16 +27,18 @@ interpretation "weight (term)" 'Weight T = (tw T).
 
 (* Basic properties *********************************************************)
 
-(* Basic_1: was: tweight_lt *)
-lemma tw_pos: ∀T. 1 ≤ ♯❨T❩.
-#T elim T -T //
-qed.
+lemma tw_atom_unfold (I): 𝟏 = ♯❨⓪[I]❩.
+// qed.
+
+lemma tw_pair_unfold (I) (V) (T): ↑(♯❨V❩ + ♯❨T❩) = ♯❨②[I]V.T❩.
+// qed.
 
 lemma tw_le_pair_dx (I): ∀V,T. ♯❨T❩ < ♯❨②[I]V.T❩.
-#I #V #T /2 width=1 by nle_succ_bi/
+/2 width=1 by plt_succ_dx_trans/
 qed.
 
-(* Basic_1: removed theorems 11:
+(* Basic_1: removed theorems 12:
+            tweight_lt
             wadd_le wadd_lt wadd_O weight_le weight_eq weight_add_O
             weight_add_S tlt_trans tlt_head_sx tlt_head_dx tlt_wf_ind
 *)