let X be non empty set ; for S being SigmaField of X
for f, g being PartFunc of X,REAL
for A being Element of S st A c= dom f & f is A -measurable & g is A -measurable holds
(max+ (f + g)) + (max- f) is A -measurable
let S be SigmaField of X; for f, g being PartFunc of X,REAL
for A being Element of S st A c= dom f & f is A -measurable & g is A -measurable holds
(max+ (f + g)) + (max- f) is A -measurable
let f, g be PartFunc of X,REAL; for A being Element of S st A c= dom f & f is A -measurable & g is A -measurable holds
(max+ (f + g)) + (max- f) is A -measurable
let A be Element of S; ( A c= dom f & f is A -measurable & g is A -measurable implies (max+ (f + g)) + (max- f) is A -measurable )
assume that
A1:
A c= dom f
and
A2:
f is A -measurable
and
A3:
g is A -measurable
; (max+ (f + g)) + (max- f) is A -measurable
f + g is A -measurable
by A2, A3, Th26;
then A4:
max+ (f + g) is A -measurable
by Th46;
max- f is A -measurable
by A1, A2, Th47;
hence
(max+ (f + g)) + (max- f) is A -measurable
by A4, Th26; verum