theorem Th3: :: FINANCE3:27

for Sigma being SigmaField of {1,2,3,4}
for I being set st I = {1,2,3} & Sigma = bool {1,2,3,4} holds
ex MyFunc being ManySortedSigmaField of I,Sigma st
( MyFunc . 1 = Special_SigmaField1 & MyFunc . 2 = Special_SigmaField2 & MyFunc . 3 = Special_SigmaField3 )