Metamath Proof Explorer


Theorem ltsirr

Description: Surreal less-than is irreflexive. (Contributed by Scott Fenton, 16-Jun-2011)

Ref Expression
Assertion ltsirr ⊢ A ∈ No → ¬ A < s A

Proof

Step Hyp Ref Expression
1 ltsso ⊢ < s Or No
2 sonr ⊢ < s Or No ∧ A ∈ No → ¬ A < s A
3 1 2 mpan ⊢ A ∈ No → ¬ A < s A