Metamath Proof Explorer


Theorem disllycmp

Description: A discrete space is locally compact. (Contributed by Mario Carneiro, 20-Mar-2015)

Ref Expression
Assertion disllycmp
|- ( X e. V -> ~P X e. Locally Comp )

Proof

Step Hyp Ref Expression
1 snfi
 |-  { x } e. Fin
2 discmp
 |-  ( { x } e. Fin <-> ~P { x } e. Comp )
3 1 2 mpbi
 |-  ~P { x } e. Comp
4 3 rgenw
 |-  A. x e. X ~P { x } e. Comp
5 dislly
 |-  ( X e. V -> ( ~P X e. Locally Comp <-> A. x e. X ~P { x } e. Comp ) )
6 4 5 mpbiri
 |-  ( X e. V -> ~P X e. Locally Comp )