let X be non empty set ; for S being SigmaField of X
for E being Element of S
for f, g being PartFunc of X,REAL st (dom f) /\ (dom g) = E & f is E -measurable & g is E -measurable holds
f (#) g is E -measurable
let S be SigmaField of X; for E being Element of S
for f, g being PartFunc of X,REAL st (dom f) /\ (dom g) = E & f is E -measurable & g is E -measurable holds
f (#) g is E -measurable
let E be Element of S; for f, g being PartFunc of X,REAL st (dom f) /\ (dom g) = E & f is E -measurable & g is E -measurable holds
f (#) g is E -measurable
let f, g be PartFunc of X,REAL; ( (dom f) /\ (dom g) = E & f is E -measurable & g is E -measurable implies f (#) g is E -measurable )
assume that
A1:
(dom f) /\ (dom g) = E
and
A2:
( f is E -measurable & g is E -measurable )
; f (#) g is E -measurable
( R_EAL f is E -measurable & R_EAL g is E -measurable )
by A2, MESFUNC6:def 1;
then
(R_EAL f) (#) (R_EAL g) is E -measurable
by A1, MESFUNC7:15;
then
R_EAL (f (#) g) is E -measurable
by Th30;
hence
f (#) g is E -measurable
by MESFUNC6:def 1; verum