let L be non empty RelStr ; for T1, T2 being correct TopAugmentation of L
for T being Refinement of T1,T2 holds INTERSECTION ( the topology of T1, the topology of T2) is Basis of T
let T1, T2 be correct TopAugmentation of L; for T being Refinement of T1,T2 holds INTERSECTION ( the topology of T1, the topology of T2) is Basis of T
A1:
RelStr(# the carrier of T1, the InternalRel of T1 #) = RelStr(# the carrier of L, the InternalRel of L #)
by Def4;
RelStr(# the carrier of T2, the InternalRel of T2 #) = RelStr(# the carrier of L, the InternalRel of L #)
by Def4;
hence
for T being Refinement of T1,T2 holds INTERSECTION ( the topology of T1, the topology of T2) is Basis of T
by A1, Th60; verum