let X be non empty set ; :: thesis: 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; :: thesis: 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 ; :: thesis: 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; :: thesis: 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; :: thesis: ( 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 A2: ( f is_measurable_on A & A c= dom f ) ; :: thesis: (A /\ (great_dom f,r)) /\ (less_dom f,s) in S
then R_EAL f is_measurable_on A by Def6;
hence (A /\ (great_dom f,r)) /\ (less_dom f,s) in S by A2, A1, MESFUNC1:36; :: thesis: verum