Theorem r2al 3195

Description: Double restricted universal quantification. (Contributed by NM, 19-Nov-1995.) Reduce dependencies on axioms. (Revised by Wolf Lammen, 9-Jan-2020.)

Assertion

Ref	Expression
r2al	⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ ∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑))

Distinct variable groups:   𝑥,𝑦   𝑦,𝐴

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

Proof of Theorem r2al

Step	Hyp	Ref	Expression
1		19.21v 1943	. 2 ⊢ (∀𝑦(𝑥 ∈ 𝐴 → (𝑦 ∈ 𝐵 → 𝜑)) ↔ (𝑥 ∈ 𝐴 → ∀𝑦(𝑦 ∈ 𝐵 → 𝜑)))
2	1	r2allem 3143	1 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ ∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 397  ∀wal 1540   ∈ wcel 2107  ∀wral 3062

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1914

This theorem depends on definitions:  df-bi 206  df-an 398  df-ex 1783  df-ral 3063

This theorem is referenced by:  r2ex  3196  r3al  3197  ralcom  3287  nfra2w  3297  moel  3399  raliunxp  5840  codir  6122  qfto  6123  dfpo2  6296  fununi  6624  dff13  7254  mpo2eqb  7541  frpoins3xpg  8126  xpord2indlem  8133  tz7.48lem  8441  qliftfun  8796  zorn2lem4  10494  isirred2  20235  cnmpt12  23171  cnmpt22  23178  dchrelbas3  26741  cvmlift2lem12  34305  dfso2  34725  r2alan  37116  inxpss  37180  inxpss3  37183  isdomn3  41946  iscnrm3lem2  47567  joindm2  47601  meetdm2  47603