theorem :: FINTOPO2:31

for FMT being non empty FMT_Space_Str holds
( ( for x being Element of FMT
for V1, V2 being Subset of FMT st V1 in U_FMT x & V2 in U_FMT x holds
ex W being Subset of FMT st
( W in U_FMT x & W c= V1 /\ V2 ) ) iff for A, B being Subset of FMT holds (A ^Foi) /\ (B ^Foi) = (A /\ B) ^Foi )