theorem Th23: :: MESFUN13:26
for X being non empty set
for S being SigmaField of X
for M being sigma_Measure of S
for A being Element of S
for f being PartFunc of X,ExtREAL st M . A = 0 & A c= dom f & f | (A `) is_integrable_on M holds
ex g being PartFunc of X,ExtREAL st
( dom g = dom f & f | (A `) = g | (A `) & g is_integrable_on M & Integral (M,(f | (A `))) = Integral (M,g) )