let A be non empty set ; for f, g being Element of Funcs A,REAL holds (RealFuncMult A) . f,g = (RealFuncMult A) . g,f
let f, g be Element of Funcs A,REAL ; (RealFuncMult A) . f,g = (RealFuncMult A) . g,f
hence
(RealFuncMult A) . f,g = (RealFuncMult A) . g,f
by FUNCT_2:113; verum