let X, Y be non empty set ; for F being BinOp of X
for f being Function of Y,X
for x being Element of X
for y being Element of Y holds (F [;] (x,f)) . y = F . (x,(f . y))
let F be BinOp of X; for f being Function of Y,X
for x being Element of X
for y being Element of Y holds (F [;] (x,f)) . y = F . (x,(f . y))
let f be Function of Y,X; for x being Element of X
for y being Element of Y holds (F [;] (x,f)) . y = F . (x,(f . y))
let x be Element of X; for y being Element of Y holds (F [;] (x,f)) . y = F . (x,(f . y))
let y be Element of Y; (F [;] (x,f)) . y = F . (x,(f . y))
dom (F [;] (x,f)) = Y
by FUNCT_2:def 1;
hence
(F [;] (x,f)) . y = F . (x,(f . y))
by Th32; verum