Metamath Proof Explorer


Theorem rspec2

Description: Specialization rule for restricted quantification, with two quantifiers. (Contributed by NM, 20-Nov-1994)

Ref Expression
Hypothesis rspec2.1 𝑥𝐴𝑦𝐵 𝜑
Assertion rspec2 ( ( 𝑥𝐴𝑦𝐵 ) → 𝜑 )

Proof

Step Hyp Ref Expression
1 rspec2.1 𝑥𝐴𝑦𝐵 𝜑
2 1 rspec ( 𝑥𝐴 → ∀ 𝑦𝐵 𝜑 )
3 2 r19.21bi ( ( 𝑥𝐴𝑦𝐵 ) → 𝜑 )