Theorem sonr

Description: A strict order relation is irreflexive. (Contributed by NM, 24-Nov-1995)

	Ref	Expression
Assertion	sonr	⊢ ( ( 𝑅 Or 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ¬ 𝐵 𝑅 𝐵 )

Proof

Step	Hyp	Ref	Expression
1		sopo	⊢ ( 𝑅 Or 𝐴 → 𝑅 Po 𝐴 )
2		poirr	⊢ ( ( 𝑅 Po 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ¬ 𝐵 𝑅 𝐵 )
3	1 2	sylan	⊢ ( ( 𝑅 Or 𝐴 ∧ 𝐵 ∈ 𝐴 ) → ¬ 𝐵 𝑅 𝐵 )