(* *)
(**************************************************************************)
-set "baseuri" "cic:/matita/Z/z".
-
include "datatypes/bool.ma".
include "nat/nat.ma".
[ O \Rightarrow OZ
| (S n)\Rightarrow pos n].
-coercion cic:/matita/Z/z/Z_of_nat.con.
+coercion Z_of_nat.
definition neg_Z_of_nat \def
\lambda n. match n with