let PM be MetrStruct ; :: thesis: TopStruct(# the carrier of PM,(Family_open_set PM) #) is TopSpace
set T = TopStruct(# the carrier of PM,(Family_open_set PM) #);
A1: for p, q being Subset of TopStruct(# the carrier of PM,(Family_open_set PM) #) st p in the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) & q in the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) holds
p /\ q in the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) by Th35;
( the carrier of TopStruct(# the carrier of PM,(Family_open_set PM) #) in the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) & ( for a being Subset-Family of TopStruct(# the carrier of PM,(Family_open_set PM) #) st a c= the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) holds
union a in the topology of TopStruct(# the carrier of PM,(Family_open_set PM) #) ) ) by Th34, Th36;
hence TopStruct(# the carrier of PM,(Family_open_set PM) #) is TopSpace by A1, PRE_TOPC:def 1; :: thesis: verum