let C be AltCatStr ; ( C is quasi-discrete implies C is transitive )
assume A1:
C is quasi-discrete
; C is transitive
let o1, o2, o3 be object of C; ALTCAT_1:def 4 ( <^o1,o2^> <> {} & <^o2,o3^> <> {} implies <^o1,o3^> <> {} )
assume
( <^o1,o2^> <> {} & <^o2,o3^> <> {} )
; <^o1,o3^> <> {}
hence
<^o1,o3^> <> {}
by A1, Def20; verum