let B be non empty subcategory of A; ( B is full implies B is with_all_isomorphisms )
assume A1:
B is full
; B is with_all_isomorphisms
let a, b be Object of B; YELLOW21:def 8 for f being Function of (latt a),(latt b) st f is isomorphic holds
f in <^a,b^>
let f be Function of (latt a),(latt b); ( f is isomorphic implies f in <^a,b^> )
reconsider a9 = a, b9 = b as Object of A by ALTCAT_2:29;
assume
f is isomorphic
; f in <^a,b^>
then
f in <^a9,b9^>
by Def8;
hence
f in <^a,b^>
by A1, ALTCAT_2:28; verum