Metamath Proof Explorer


Theorem noprc

Description: The surreal numbers are a proper class. (Contributed by Scott Fenton, 16-Jun-2011)

Ref Expression
Assertion noprc ⊢ ¬ No ∈ V

Proof

Step Hyp Ref Expression
1 onprc ⊢ ¬ On ∈ V
2 bdayfo ⊢ bday : No ⟶ onto On
3 focdmex ⊢ No ∈ V → bday : No ⟶ onto On → On ∈ V
4 2 3 mpi ⊢ No ∈ V → On ∈ V
5 1 4 mto ⊢ ¬ No ∈ V