let A be non empty set ; :: thesis: for f, g being Element of Funcs (A,REAL) holds (maxfuncreal A) . (f,g) = (maxfuncreal A) . (g,f)
let f, g be Element of Funcs (A,REAL); :: thesis: (maxfuncreal A) . (f,g) = (maxfuncreal A) . (g,f)

now

let x be Element of A; :: thesis: ((maxfuncreal A) . (f,g)) . x = ((maxfuncreal A) . (g,f)) . x
A1: x in dom (maxreal .: (f,g)) by Lm8;
A2: x in dom (maxreal .: (g,f)) by Lm8;
thus ((maxfuncreal A) . (f,g)) . x = (maxreal .: (f,g)) . x by Def5
.= maxreal . ((f . x),(g . x)) by A1, FUNCOP_1:28
.= maxreal . ((g . x),(f . x)) by Th8
.= (maxreal .: (g,f)) . x by A2, FUNCOP_1:28
.= ((maxfuncreal A) . (g,f)) . x by Def5 ; :: thesis: verum

end;

hence (maxfuncreal A) . (f,g) = (maxfuncreal A) . (g,f) by FUNCT_2:113; :: thesis: verum