let p, s be ext-real number ; :: thesis: ( p <= s implies [.p,+infty .] \ ].p,s.] = {p} \/ ].s,+infty .] )
p <= +infty by XXREAL_0:3;
hence ( p <= s implies [.p,+infty .] \ ].p,s.] = {p} \/ ].s,+infty .] ) by Th324; :: thesis: verum