Metamath Proof Explorer


Theorem rgen2w

Description: Generalization rule for restricted quantification. Note that x and y needn't be distinct. (Contributed by NM, 18-Jun-2014)

Ref Expression
Hypothesis rgenw.1 ⊢ 𝜑
Assertion rgen2w ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 𝜑

Proof

Step Hyp Ref Expression
1 rgenw.1 ⊢ 𝜑
2 1 rgenw ⊢ ∀ 𝑦 ∈ 𝐵 𝜑
3 2 rgenw ⊢ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 𝜑