Let-S-be-a-nonempty-subset-of-R-that-is-bounded-below-prove-that-inf-S-sup-s-s-S-

Question Number 103180 by mohammad17 last updated on 13/Jul/20

L e t S b e a n o n e m p t y s u b s e t o f R t h a t i s b o u n d e d

b e l o w . p r o v e t h a t (i n f (S) = - s u p {- s : s \in S}) ?