let C be non empty AltCatStr ; for D being non empty SubCatStr of C
for o1, o2 being Object of C
for p1, p2 being Object of D st o1 = p1 & o2 = p2 & <^p1,p2^> <> {} holds
for n being Morphism of p1,p2 holds n is Morphism of o1,o2
let D be non empty SubCatStr of C; for o1, o2 being Object of C
for p1, p2 being Object of D st o1 = p1 & o2 = p2 & <^p1,p2^> <> {} holds
for n being Morphism of p1,p2 holds n is Morphism of o1,o2
let o1, o2 be Object of C; for p1, p2 being Object of D st o1 = p1 & o2 = p2 & <^p1,p2^> <> {} holds
for n being Morphism of p1,p2 holds n is Morphism of o1,o2
let p1, p2 be Object of D; ( o1 = p1 & o2 = p2 & <^p1,p2^> <> {} implies for n being Morphism of p1,p2 holds n is Morphism of o1,o2 )
assume A1:
( o1 = p1 & o2 = p2 & <^p1,p2^> <> {} )
; for n being Morphism of p1,p2 holds n is Morphism of o1,o2
let n be Morphism of p1,p2; n is Morphism of o1,o2
( n in <^p1,p2^> & <^p1,p2^> c= <^o1,o2^> )
by A1, Th31;
hence
n is Morphism of o1,o2
; verum