take
[.0,1.]
; ( not [.0,1.] is empty & [.0,1.] is closed_interval )
thus
not [.0,1.] is empty
by XXREAL_1:30; [.0,1.] is closed_interval
take
0
; MEASURE5:def 3 ex b being Real st [.0,1.] = [.0,b.]
take
1
; [.0,1.] = [.0,1.]
thus
[.0,1.] = [.0,1.]
; verum