theorem Th5: :: MEASUR11:11

for X1, X2 being non empty set
for S1 being SigmaField of X1
for S2 being SigmaField of X2
for M1 being sigma_Measure of S1
for M2 being sigma_Measure of S2
for A being Element of S1
for B being Element of S2 holds (product_Measure (M1,M2)) . [:A,B:] = (M1 . A) * (M2 . B)