(* Basic_1: was: sn3_appls_cast *)
lemma csn_applv_tau: ∀L,W. L ⊢ ⬇* W →
∀Vs,T. L ⊢ ⬇* ⒶVs. T →
- L â\8a¢ â¬\87* â\92¶Vs. â\93£W. T.
+ L â\8a¢ â¬\87* â\92¶Vs. â\93\9dW. T.
#L #W #HW #Vs elim Vs -Vs /2 width=1/ -HW
#V #Vs #IHV #T #H1T
lapply (csn_fwd_pair_sn … H1T) #HV