Metamath Proof Explorer


Theorem onintopssconn

Description: An ordinal topology is connected, expressed in constants. (Contributed by Chen-Pang He, 16-Oct-2015)

Ref Expression
Assertion onintopssconn
|- ( On i^i Top ) C_ Conn

Proof

Step Hyp Ref Expression
1 elin
 |-  ( x e. ( On i^i Top ) <-> ( x e. On /\ x e. Top ) )
2 eloni
 |-  ( x e. On -> Ord x )
3 ordtopconn
 |-  ( Ord x -> ( x e. Top <-> x e. Conn ) )
4 2 3 syl
 |-  ( x e. On -> ( x e. Top <-> x e. Conn ) )
5 4 biimpa
 |-  ( ( x e. On /\ x e. Top ) -> x e. Conn )
6 1 5 sylbi
 |-  ( x e. ( On i^i Top ) -> x e. Conn )
7 6 ssriv
 |-  ( On i^i Top ) C_ Conn