Theorem r2ex 3202

Description: Double restricted existential quantification. (Contributed by NM, 11-Nov-1995.) Reduce dependencies on axioms. (Revised by Wolf Lammen, 10-Jan-2020.)

Assertion

Ref	Expression
r2ex	⊢ (∃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 r2ex

Step	Hyp	Ref	Expression
1		r2al 3201	. 2 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 ¬ 𝜑 ↔ ∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → ¬ 𝜑))
2	1	r2exlem 3149	1 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜑 ↔ ∃𝑥∃𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) ∧ 𝜑))

Syntax hints:  ¬ wn 3   ↔ wb 206   ∧ wa 395  ∃wex 1777   ∈ wcel 2108  ∃wrex 3076

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909

This theorem depends on definitions:  df-bi 207  df-an 396  df-ex 1778  df-ral 3068  df-rex 3077

This theorem is referenced by:  r3ex  3204  reeanlem  3234  elxp2  5724  elinxp  6048  rnoprab2  7555  elrnmpores  7588  oeeu  8659  omxpenlem  9139  axcnre  11233  hash2prb  14521  hashle2prv  14527  pmtrrn2  19502  fsumvma  27275  umgredg  29173  fusgr2wsp2nb  30366  spanuni  31576  5oalem7  31692  3oalem3  31696  trsp2cyc  33116  fmla0xp  35351  elfuns  35879  ellines  36116  dalem20  39650  diblsmopel  41128  iunrelexpuztr  43681  sprssspr  47355  prprelb  47390