let o, m be set ; for a, b being Object of (c1Cat* (o,m))
for f being Morphism of (c1Cat* (o,m)) holds f in Hom (a,b)
let a, b be Object of (c1Cat* (o,m)); for f being Morphism of (c1Cat* (o,m)) holds f in Hom (a,b)
let f be Morphism of (c1Cat* (o,m)); f in Hom (a,b)
cod f = o
by TARSKI:def 1;
then A1:
cod f = b
by TARSKI:def 1;
dom f = o
by TARSKI:def 1;
then
dom f = a
by TARSKI:def 1;
hence
f in Hom (a,b)
by A1; verum