Metamath Proof Explorer


Theorem esumeq2sdv

Description: Equality deduction for extended sum. (Contributed by Thierry Arnoux, 25-Dec-2016)

Ref Expression
Hypothesis esumeq2sdv.1 ⊢ ( 𝜑 → 𝐵 = 𝐶 )
Assertion esumeq2sdv ( 𝜑 → Σ* 𝑘 ∈ 𝐴 𝐵 = Σ* 𝑘 ∈ 𝐴 𝐶 )

Proof

Step Hyp Ref Expression
1 esumeq2sdv.1 ⊢ ( 𝜑 → 𝐵 = 𝐶 )
2 1 adantr ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐴 ) → 𝐵 = 𝐶 )
3 2 esumeq2dv ⊢ ( 𝜑 → Σ* 𝑘 ∈ 𝐴 𝐵 = Σ* 𝑘 ∈ 𝐴 𝐶 )