Metamath Proof Explorer


Theorem nnct

Description: NN is countable. (Contributed by Thierry Arnoux, 29-Dec-2016)

Ref Expression
Assertion nnct ℕ ≼ ω

Proof

Step Hyp Ref Expression
1 nnenom ℕ ≈ ω
2 endom ( ℕ ≈ ω → ℕ ≼ ω )
3 1 2 ax-mp ℕ ≼ ω