let X be non empty set ; for S being SigmaField of X
for f being PartFunc of X,REAL
for A being Element of S
for r, s being Real st f is_measurable_on A & A c= dom f holds
(A /\ (great_dom f,r)) /\ (less_dom f,s) in S
let S be SigmaField of X; for f being PartFunc of X,REAL
for A being Element of S
for r, s being Real st f is_measurable_on A & A c= dom f holds
(A /\ (great_dom f,r)) /\ (less_dom f,s) in S
let f be PartFunc of X,REAL ; for A being Element of S
for r, s being Real st f is_measurable_on A & A c= dom f holds
(A /\ (great_dom f,r)) /\ (less_dom f,s) in S
let A be Element of S; for r, s being Real st f is_measurable_on A & A c= dom f holds
(A /\ (great_dom f,r)) /\ (less_dom f,s) in S
let r, s be Real; ( f is_measurable_on A & A c= dom f implies (A /\ (great_dom f,r)) /\ (less_dom f,s) in S )
A1:
( R_EAL r = r & R_EAL s = s )
;
assume that
A2:
f is_measurable_on A
and
A3:
A c= dom f
; (A /\ (great_dom f,r)) /\ (less_dom f,s) in S
R_EAL f is_measurable_on A
by A2, Def6;
hence
(A /\ (great_dom f,r)) /\ (less_dom f,s) in S
by A1, A3, MESFUNC1:36; verum