Metamath Proof Explorer


Theorem 0cmp

Description: The singleton of the empty set is compact. (Contributed by FL, 2-Aug-2009)

Ref Expression
Assertion 0cmp ⊢ ∅ ∈ Comp

Proof

Step Hyp Ref Expression
1 sn0top ⊢ ∅ ∈ Top
2 snfi ⊢ ∅ ∈ Fin
3 1 2 elini ⊢ ∅ ∈ Top ∩ Fin
4 fincmp ⊢ ∅ ∈ Top ∩ Fin → ∅ ∈ Comp
5 3 4 ax-mp ⊢ ∅ ∈ Comp