let A, B be non empty reflexive AltGraph ; for F being BimapStr of A,B st F is coreflexive holds
for o being object of B ex o9 being object of A st F . o9 = o
let F be BimapStr of A,B; ( F is coreflexive implies for o being object of B ex o9 being object of A st F . o9 = o )
assume
F is coreflexive
; for o being object of B ex o9 being object of A st F . o9 = o
then A1:
id the carrier of B c= the ObjectMap of F .: (id the carrier of A)
by Def10;
let o be object of B; ex o9 being object of A st F . o9 = o
reconsider oo = [o,o] as Element of [: the carrier of B, the carrier of B:] by ZFMISC_1:106;
[o,o] in id the carrier of B
by RELAT_1:def 10;
then consider pp being Element of [: the carrier of A, the carrier of A:] such that
A2:
pp in id the carrier of A
and
A3:
the ObjectMap of F . pp = oo
by A1, FUNCT_2:116;
consider p, p9 being set such that
A4:
pp = [p,p9]
by RELAT_1:def 1;
A5:
p = p9
by A2, A4, RELAT_1:def 10;
reconsider p = p as object of A by A2, A4, RELAT_1:def 10;
take
p
; F . p = o
thus
F . p = o
by A3, A4, A5, MCART_1:7; verum