let C1, C2 be non empty AltCatStr ; ( the carrier of C2 = the carrier of C1 & the Arrows of C2 = ~ the Arrows of C1 & ( for a, b, c being Object of C1
for a9, b9, c9 being Object of C2 st a9 = a & b9 = b & c9 = c holds
the Comp of C2 . (a9,b9,c9) = ~ ( the Comp of C1 . (c,b,a)) ) implies ( the carrier of C1 = the carrier of C2 & the Arrows of C1 = ~ the Arrows of C2 & ( for a, b, c being Object of C2
for a9, b9, c9 being Object of C1 st a9 = a & b9 = b & c9 = c holds
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a)) ) ) )
assume that
A1:
the carrier of C2 = the carrier of C1
and
A2:
the Arrows of C2 = ~ the Arrows of C1
and
A3:
for a, b, c being Object of C1
for a9, b9, c9 being Object of C2 st a9 = a & b9 = b & c9 = c holds
the Comp of C2 . (a9,b9,c9) = ~ ( the Comp of C1 . (c,b,a))
; ( the carrier of C1 = the carrier of C2 & the Arrows of C1 = ~ the Arrows of C2 & ( for a, b, c being Object of C2
for a9, b9, c9 being Object of C1 st a9 = a & b9 = b & c9 = c holds
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a)) ) )
thus
the carrier of C1 = the carrier of C2
by A1; ( the Arrows of C1 = ~ the Arrows of C2 & ( for a, b, c being Object of C2
for a9, b9, c9 being Object of C1 st a9 = a & b9 = b & c9 = c holds
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a)) ) )
dom the Arrows of C1 = [: the carrier of C1, the carrier of C1:]
by PARTFUN1:def 2;
hence
the Arrows of C1 = ~ the Arrows of C2
by A2, FUNCT_4:52; for a, b, c being Object of C2
for a9, b9, c9 being Object of C1 st a9 = a & b9 = b & c9 = c holds
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a))
let a, b, c be Object of C2; for a9, b9, c9 being Object of C1 st a9 = a & b9 = b & c9 = c holds
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a))
let a9, b9, c9 be Object of C1; ( a9 = a & b9 = b & c9 = c implies the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a)) )
assume that
A4:
a9 = a
and
A5:
b9 = b
and
A6:
c9 = c
; the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a))
A7:
the Comp of C2 . (c,b,a) = ~ ( the Comp of C1 . (a9,b9,c9))
by A3, A4, A5, A6;
dom ( the Comp of C1 . (a9,b9,c9)) c= [:( the Arrows of C1 . (b9,c9)),( the Arrows of C1 . (a9,b9)):]
;
hence
the Comp of C1 . (a9,b9,c9) = ~ ( the Comp of C2 . (c,b,a))
by A7, FUNCT_4:52; verum