theorem Th14: :: PENCIL_3:14

for I being non empty set
for A being PLS-yielding ManySortedSet of I
for i being Element of I
for S being Subset of (A . i)
for L being non trivial-yielding Segre-like ManySortedSubset of Carrier A holds product (L +* (i,S)) is Subset of (Segre_Product A)