Metamath Proof Explorer


Theorem eqeltrrdi

Description: A membership and equality inference. (Contributed by NM, 4-Jan-2006)

Ref Expression
Hypotheses eqeltrrdi.1 ⊢ ( 𝜑 → 𝐵 = 𝐴 )
eqeltrrdi.2 ⊢ 𝐵 ∈ 𝐶
Assertion eqeltrrdi ( 𝜑 → 𝐴 ∈ 𝐶 )

Proof

Step Hyp Ref Expression
1 eqeltrrdi.1 ⊢ ( 𝜑 → 𝐵 = 𝐴 )
2 eqeltrrdi.2 ⊢ 𝐵 ∈ 𝐶
3 1 eqcomd ⊢ ( 𝜑 → 𝐴 = 𝐵 )
4 3 2 eqeltrdi ⊢ ( 𝜑 → 𝐴 ∈ 𝐶 )