List.ma: added function nth (with default value in case of failure)

[helm.git] / matita / tests / coercions.ma

diff --git a/matita/tests/coercions.ma b/matita/tests/coercions.ma
index dc4e030bd45d5d0e925948546d0027a2964f110b..8e7582a147113a99b67e93e6bf484fe2865efb26 100644 (file)
--- a/matita/tests/coercions.ma
+++ b/matita/tests/coercions.ma
@@ -59,10 +59,14 @@ definition double2:
 \def 
   \lambda f:int \to int. \lambda x : pos .f (nat2int (pos2nat x)).
 
+(* This used to test eq_f as a coercion. However, posing both eq_f and sym_eq
+   as coercions made the qed time of some TPTP problems reach infty.
+   Thus eq_f is no longer a coercion (nor is sym_eq).
 theorem coercion_svelta : \forall T,S:Type.\forall f:T \to S.\forall x,y:T.x=y \to f y = f x.
   intros.
   apply ((\lambda h:f y = f x.h) H).
 qed.
+*)
 
 variant pos2nat' : ? \def pos2nat.
 
@@ -105,7 +109,8 @@ definition church: nat \to nat \to nat \def times.
 coercion cic:/matita/tests/coercions/church.con 1.
 
 definition mapmult:  \forall n:nat.\forall l:listn nat n. nat \to nat \to nat \def
-  \lambda n:nat.\lambda l:listn nat n.\lambda m,o:nat.l m o.
+  \lambda n:nat.\lambda l:listn nat n.\lambda m,o:nat.
+  l (m m) o (o o o).