for X being non empty set
for S being SigmaField of X
for M being sigma_Measure of S
for f being PartFunc of X,ExtREAL st f is_integrable_on M holds
( 0 <= integral+ (M,(max+ f)) & 0 <= integral+ (M,(max- f)) & -infty < Integral (M,f) & Integral (M,f) < +infty )