Metamath Proof Explorer


Theorem prodeq12rdv

Description: Equality deduction for product. (Contributed by Scott Fenton, 4-Dec-2017)

Ref Expression
Hypotheses prodeq12rdv.1 ⊢ ( 𝜑 → 𝐴 = 𝐵 )
prodeq12rdv.2 ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐵 ) → 𝐶 = 𝐷 )
Assertion prodeq12rdv ( 𝜑 → ∏ 𝑘 ∈ 𝐴 𝐶 = ∏ 𝑘 ∈ 𝐵 𝐷 )

Proof

Step Hyp Ref Expression
1 prodeq12rdv.1 ⊢ ( 𝜑 → 𝐴 = 𝐵 )
2 prodeq12rdv.2 ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐵 ) → 𝐶 = 𝐷 )
3 1 prodeq1d ⊢ ( 𝜑 → ∏ 𝑘 ∈ 𝐴 𝐶 = ∏ 𝑘 ∈ 𝐵 𝐶 )
4 2 prodeq2dv ⊢ ( 𝜑 → ∏ 𝑘 ∈ 𝐵 𝐶 = ∏ 𝑘 ∈ 𝐵 𝐷 )
5 3 4 eqtrd ⊢ ( 𝜑 → ∏ 𝑘 ∈ 𝐴 𝐶 = ∏ 𝑘 ∈ 𝐵 𝐷 )