let F be sequence of (bool REAL); for G being Open_Interval_Covering of F
for H being sequence of [:NAT,NAT:] st rng H = [:NAT,NAT:] holds
On (G,H) is Open_Interval_Covering of union (rng F)
let G be Open_Interval_Covering of F; for H being sequence of [:NAT,NAT:] st rng H = [:NAT,NAT:] holds
On (G,H) is Open_Interval_Covering of union (rng F)
let H be sequence of [:NAT,NAT:]; ( rng H = [:NAT,NAT:] implies On (G,H) is Open_Interval_Covering of union (rng F) )
assume A1:
rng H = [:NAT,NAT:]
; On (G,H) is Open_Interval_Covering of union (rng F)
for n being Element of NAT holds (On (G,H)) . n is open_interval
hence
On (G,H) is Open_Interval_Covering of union (rng F)
by Def5; verum