let it1, it2 be Function of [:COMPLEX ,(Funcs X,the carrier of Y):],(Funcs X,the carrier of Y); ( ( for c being Complex
for f being Element of Funcs X,the carrier of Y
for x being Element of X holds (it1 . [c,f]) . x = c * (f . x) ) & ( for c being Complex
for f being Element of Funcs X,the carrier of Y
for x being Element of X holds (it2 . [c,f]) . x = c * (f . x) ) implies it1 = it2 )
assume that
A1:
for c being Complex
for f being Element of Funcs X,the carrier of Y
for x being Element of X holds (it1 . [c,f]) . x = c * (f . x)
and
A2:
for c being Complex
for f being Element of Funcs X,the carrier of Y
for x being Element of X holds (it2 . [c,f]) . x = c * (f . x)
; it1 = it2
hence
it1 = it2
by BINOP_1:2; verum