Theorem 19.9d2r 32449

Description: A deduction version of one direction of 19.9 2208 with two variables. (Contributed by Thierry Arnoux, 30-Jan-2017.)

Hypotheses

Ref	Expression
19.9d2r.1	⊢ (𝜑 → Ⅎ𝑥𝜓)
19.9d2r.2	⊢ (𝜑 → Ⅎ𝑦𝜓)
19.9d2r.3	⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜓)

Assertion

Ref	Expression
19.9d2r	⊢ (𝜑 → 𝜓)

Distinct variable group:   𝜑,𝑦

Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑥,𝑦)   𝐴(𝑥,𝑦)   𝐵(𝑥,𝑦)

Proof of Theorem 19.9d2r

Step	Hyp	Ref	Expression
1		nfv 1915	. 2 ⊢ Ⅎ𝑦𝜑
2		19.9d2r.1	. 2 ⊢ (𝜑 → Ⅎ𝑥𝜓)
3		19.9d2r.2	. 2 ⊢ (𝜑 → Ⅎ𝑦𝜓)
4		19.9d2r.3	. 2 ⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜓)
5	1, 2, 3, 4	19.9d2rf 32448	1 ⊢ (𝜑 → 𝜓)

Syntax hints:   → wi 4  Ⅎwnf 1784  ∃wrex 3056

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-10 2144  ax-11 2160  ax-12 2180

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-ex 1781  df-nf 1785  df-rex 3057

This theorem is referenced by:  xrofsup  32750