Dummy dependent types are no longer cleaned in inductive type arities.

[helm.git] / helm / software / matita / library / nat / relevant_equations.ma

diff --git a/helm/software/matita/library/nat/relevant_equations.ma b/helm/software/matita/library/nat/relevant_equations.ma
index 9e275aa9ca8a6e8828af7fab7c7073b502cd26b7..a2ef6e40cdc6ffaba378c058d3a030a6fa9bea9d 100644 (file)
--- a/helm/software/matita/library/nat/relevant_equations.ma
+++ b/helm/software/matita/library/nat/relevant_equations.ma
@@ -12,8 +12,6 @@
 (*                                                                        *)
 (**************************************************************************)
 
-set "baseuri" "cic:/matita/nat/relevant_equations".
-
 include "nat/times.ma".
 include "nat/minus.ma".
 include "nat/gcd.ma". 
@@ -50,3 +48,13 @@ rewrite > distr_times_plus.
 rewrite > distr_times_plus.
 rewrite < assoc_plus.reflexivity.
 qed.
+
+theorem eq_pred_to_eq:
+ ∀n,m. O < n → O < m → pred n = pred m → n = m.
+intros;
+generalize in match (eq_f ? ? S ? ? H2);
+intro;
+rewrite < S_pred in H3;
+rewrite < S_pred in H3;
+assumption.
+qed.