Metamath Proof Explorer


Theorem elfzoelz

Description: Reverse closure for half-open integer sets. (Contributed by Stefan O'Rear, 14-Aug-2015)

Ref Expression
Assertion elfzoelz A B ..^ C A

Proof

Step Hyp Ref Expression
1 elfzoel1 A B ..^ C B
2 elfzoel2 A B ..^ C C
3 fzof ..^ : × 𝒫
4 3 fovcl B C B ..^ C 𝒫
5 1 2 4 syl2anc A B ..^ C B ..^ C 𝒫
6 5 elpwid A B ..^ C B ..^ C
7 id A B ..^ C A B ..^ C
8 6 7 sseldd A B ..^ C A