]> matita.cs.unibo.it Git - helm.git/blobdiff - matita/matita/contribs/lambdadelta/ground/arith/ynat_succ.ma
update in ground
[helm.git] / matita / matita / contribs / lambdadelta / ground / arith / ynat_succ.ma
index 8f8fe4047d04d994e09b49e8b60f1bbfeb32ca1b..b642bc56ba9109fab574af9db164bd59f9238d4c 100644 (file)
@@ -39,7 +39,7 @@ qed.
 lemma ysucc_inf: ∞ = ↑(∞).
 // qed.
 
-(* Inversion lemmas *********************************************************)
+(* Inversions ***************************************************************)
 
 (*** ysucc_inv_inj_sn *)
 lemma eq_inv_inj_ysucc (n1) (x2):
@@ -72,7 +72,7 @@ lemma eq_inv_ysucc_bi: injective … ysucc.
 #x1 @(ynat_split_nat_inf … x1) -x1
 [ #n1 #x2 <ysucc_inj #H
   elim (eq_inv_inj_ysucc … H) -H #n2 #H1 #H2 destruct
-  /3 width=1 by eq_inv_nsucc_bi, eq_f/
+  <(eq_inv_nsucc_bi … H2) -H2 //
 | #x2 #H <(eq_inv_inf_ysucc … H) -H //
 ]
 qed-.
@@ -96,7 +96,7 @@ qed-.
 lemma eq_inv_ysucc_zero (x): ↑x = 𝟎 → ⊥.
 /2 width=2 by eq_inv_zero_ysucc/ qed-.
 
-(* Eliminators **************************************************************)
+(* Eliminations *************************************************************)
 
 (*** ynat_ind *)
 lemma ynat_ind_succ (Q:predicate …):