X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Flib%2Fbasics%2Ftypes.ma;h=f35dde531e5fe93debc3f5b0e54ebb78c8f9425b;hb=844794906f5a9f97406d72b5305ce13fb75acf94;hp=08b99a8cb552165d09f203353a95c77625ac45c2;hpb=fe4df66869250943913c7fa534bb22305a320683;p=helm.git

diff --git a/matita/matita/lib/basics/types.ma b/matita/matita/lib/basics/types.ma
index 08b99a8cb..f35dde531 100644
--- a/matita/matita/lib/basics/types.ma
+++ b/matita/matita/lib/basics/types.ma
@@ -42,6 +42,12 @@ theorem eq_pair_fst_snd: ∀A,B.∀p:A × B.
   p = 〈 \fst p, \snd p 〉.
 #A #B #p (cases p) // qed.
 
+lemma fst_eq : ∀A,B.∀a:A.∀b:B. \fst 〈a,b〉 = a.
+// qed.
+
+lemma snd_eq : ∀A,B.∀a:A.∀b:B. \snd 〈a,b〉 = b.
+// qed.
+
 (* sum *)
 inductive Sum (A,B:Type[0]) : Type[0] ≝
   inl : A → Sum A B