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Metamath Proof Explorer

Theorem eqcomi

Description: Inference from commutative law for class equality. (Contributed by NM, 26-May-1993)

Ref Expression
Hypothesis eqcomi.1 ⊢ 𝐴 = 𝐵
Assertion eqcomi 𝐵 = 𝐴

Proof

Step Hyp Ref Expression
1 eqcomi.1 ⊢ 𝐴 = 𝐵
2 eqcom ⊢ ( 𝐴 = 𝐵 ↔ 𝐵 = 𝐴 )
3 1 2 mpbi ⊢ 𝐵 = 𝐴