let B be non empty subcategory of A; B is para-functional
consider F being ManySortedSet of A such that
A1:
for a1, a2 being Object of A holds <^a1,a2^> c= Funcs ((F . a1),(F . a2))
by YELLOW18:def 7;
set G = F | the carrier of B;
A2:
the carrier of B c= the carrier of A
by ALTCAT_2:def 11;
dom F = the carrier of A
by PARTFUN1:def 2;
then
dom (F | the carrier of B) = the carrier of B
by A2, RELAT_1:62;
then reconsider G = F | the carrier of B as ManySortedSet of B by PARTFUN1:def 2, RELAT_1:def 18;
take
G
; YELLOW18:def 7 for b1, b2 being Element of the carrier of B holds <^b1,b2^> c= Funcs ((G . b1),(G . b2))
let a1, a2 be Object of B; <^a1,a2^> c= Funcs ((G . a1),(G . a2))
reconsider b1 = a1, b2 = a2 as Object of A by A2;
( F . a1 = G . a1 & F . a2 = G . a2 )
by FUNCT_1:49;
then
( <^a1,a2^> c= <^b1,b2^> & <^b1,b2^> c= Funcs ((G . a1),(G . a2)) )
by A1, ALTCAT_2:31;
hence
<^a1,a2^> c= Funcs ((G . a1),(G . a2))
; verum