Metamath Proof Explorer


Theorem nodmord

Description: The domain of a surreal has the ordinal property. (Contributed by Scott Fenton, 16-Jun-2011)

Ref Expression
Assertion nodmord ⊢ A ∈ No → Ord ⁡ dom ⁡ A

Proof

Step Hyp Ref Expression
1 nodmon ⊢ A ∈ No → dom ⁡ A ∈ On
2 eloni ⊢ dom ⁡ A ∈ On → Ord ⁡ dom ⁡ A
3 1 2 syl ⊢ A ∈ No → Ord ⁡ dom ⁡ A