Theorem relen

Description: Equinumerosity is a relation. (Contributed by NM, 28-Mar-1998)

	Ref	Expression
Assertion	relen	⊢ Rel ≈

Proof

Step	Hyp	Ref	Expression
1		df-en	⊢ ≈ = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ∃ 𝑓 𝑓 : 𝑥 –1-1-onto→ 𝑦 }
2	1	relopabiv	⊢ Rel ≈