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Metamath Proof Explorer

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 ≈