X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Fcontribs%2FRELATIONAL%2FNPlus%2Finv.ma;h=ae1d4787071f27582fc77a47932ce9211d97154b;hb=effab341df3fb2bfe403e51d360e81c8b0455e1a;hp=99bf3a9eeaa07b3a99d4048b73fdfc15b35065c3;hpb=b7503f874120f581c9679deabe45bd3c333f1b0c;p=helm.git

diff --git a/helm/software/matita/contribs/RELATIONAL/NPlus/inv.ma b/helm/software/matita/contribs/RELATIONAL/NPlus/inv.ma
index 99bf3a9ee..ae1d47870 100644
--- a/helm/software/matita/contribs/RELATIONAL/NPlus/inv.ma
+++ b/helm/software/matita/contribs/RELATIONAL/NPlus/inv.ma
@@ -31,35 +31,23 @@ theorem nplus_inv_succ_1: \forall p,q,r. ((succ p) + q == r) \to
 qed.
 
 theorem nplus_inv_zero_2: \forall p,r. (p + zero == r) \to p = r.
- intros. inversion H; clear H; intros;
- [ auto.
- | clear H H1. destruct H2.
- ].
+ intros. inversion H; clear H; intros; subst. auto.
 qed.
 
 theorem nplus_inv_succ_2: \forall p,q,r. (p + (succ q) == r) \to 
                           \exists s. r = (succ s) \land p + q == s.
- intros. inversion H; clear H; intros;
- [ destruct H.
- | clear H1 H3 r. destruct H2; clear H2. subst. auto depth = 4.
- ].
+ intros. inversion H; clear H; intros; subst. auto depth = 4.
 qed.
 
 theorem nplus_inv_zero_3: \forall p,q. (p + q == zero) \to 
                           p = zero \land q = zero.
- intros. inversion H; clear H; intros;
- [ subst. auto
- | clear H H1. destruct H3.
- ].
+ intros. inversion H; clear H; intros; subst. auto.
 qed.
 
 theorem nplus_inv_succ_3: \forall p,q,r. (p + q == (succ r)) \to
                           \exists s. p = succ s \land (s + q == r) \lor
                                      q = succ s \land p + s == r.
- intros. inversion H; clear H; intros;
- [ subst
- | clear H1. destruct H3. clear H3. subst.
- ]; auto depth = 4.
+ intros. inversion H; clear H; intros; subst; auto depth = 4.
 qed.
 
 (* Corollaries to inversion lemmas ******************************************)
@@ -67,15 +55,13 @@ qed.
 theorem nplus_inv_succ_2_3: \forall p,q,r.
                             (p + (succ q) == (succ r)) \to p + q == r.
  intros. 
- lapply linear nplus_inv_succ_2 to H. decompose. subst.
- destruct H1. clear H1. subst. auto.
+ lapply linear nplus_inv_succ_2 to H. decompose. subst. auto.
 qed.
 
 theorem nplus_inv_succ_1_3: \forall p,q,r.
                             ((succ p) + q == (succ r)) \to p + q == r.
  intros. 
- lapply linear nplus_inv_succ_1 to H. decompose. subst.
- destruct H1. clear H1. subst. auto.
+ lapply linear nplus_inv_succ_1 to H. decompose. subst. auto.
 qed.
 
 theorem nplus_inv_eq_2_3: \forall p,q. (p + q == q) \to p = zero.