let X be non empty set ; :: thesis: for S being SigmaField of X
for f, g being PartFunc of X,REAL
for A being Element of S
for r being Real st f is_measurable_on A & g is_measurable_on A & A c= dom g holds
(A /\ (less_dom f,r)) /\ (great_dom g,r) in S

let S be SigmaField of X; :: thesis: for f, g being PartFunc of X,REAL
for A being Element of S
for r being Real st f is_measurable_on A & g is_measurable_on A & A c= dom g holds
(A /\ (less_dom f,r)) /\ (great_dom g,r) in S

let f, g be PartFunc of X,REAL ; :: thesis: for A being Element of S
for r being Real st f is_measurable_on A & g is_measurable_on A & A c= dom g holds
(A /\ (less_dom f,r)) /\ (great_dom g,r) in S

let A be Element of S; :: thesis: for r being Real st f is_measurable_on A & g is_measurable_on A & A c= dom g holds
(A /\ (less_dom f,r)) /\ (great_dom g,r) in S

let r be Real; :: thesis: ( f is_measurable_on A & g is_measurable_on A & A c= dom g implies (A /\ (less_dom f,r)) /\ (great_dom g,r) in S )
assume that
A1: ( f is_measurable_on A & g is_measurable_on A ) and
A2: A c= dom g ; :: thesis: (A /\ (less_dom f,r)) /\ (great_dom g,r) in S
( R_EAL f is_measurable_on A & R_EAL g is_measurable_on A ) by A1, Def6;
then (A /\ (less_dom f,(R_EAL r))) /\ (great_dom g,(R_EAL r)) in S by A2, MESFUNC1:40;
hence (A /\ (less_dom f,r)) /\ (great_dom g,r) in S ; :: thesis: verum