X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fstatic_2%2Fsyntax%2Fterm_weight.ma;h=bcb826bb41bf7477067c229b2116c9d48105f31a;hb=98e786e1a6bd7b621e37ba7cd4098d4a0a6f8278;hp=c8d4c974dca82b8436857609d58c565016cf2984;hpb=ff612dc35167ec0c145864c9aa8ae5e1ebe20a48;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/static_2/syntax/term_weight.ma b/matita/matita/contribs/lambdadelta/static_2/syntax/term_weight.ma
index c8d4c974d..bcb826bb4 100644
--- a/matita/matita/contribs/lambdadelta/static_2/syntax/term_weight.ma
+++ b/matita/matita/contribs/lambdadelta/static_2/syntax/term_weight.ma
@@ -27,10 +27,14 @@ interpretation "weight (term)" 'Weight T = (tw T).
 (* Basic properties *********************************************************)
 
 (* Basic_1: was: tweight_lt *)
-lemma tw_pos: ∀T. 1 ≤ ♯{T}.
+lemma tw_pos: ∀T. 1 ≤ ♯❨T❩.
 #T elim T -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/
+qed.
+
 (* Basic_1: removed theorems 11:
             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