let A be non empty set ; :: thesis: for f, g being Element of Funcs (A,REAL) holds (maxfuncreal A) . (f,((minfuncreal A) . (g,f))) = f
let f, g be Element of Funcs (A,REAL); :: thesis: (maxfuncreal A) . (f,((minfuncreal A) . (g,f))) = f
thus (maxfuncreal A) . (f,((minfuncreal A) . (g,f))) = (maxfuncreal A) . (f,((minfuncreal A) . (f,g))) by Th9
.= f by Th12 ; :: thesis: verum