Theorem 2rexbidva 3215

Description: Formula-building rule for restricted existential quantifiers (deduction form). (Contributed by NM, 15-Dec-2004.)

Hypothesis

Ref	Expression
2ralbidva.1	⊢ ((𝜑 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) → (𝜓 ↔ 𝜒))

Assertion

Ref	Expression
2rexbidva	⊢ (𝜑 → (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜓 ↔ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜒))

Distinct variable groups:   𝑥,𝑦,𝜑   𝑦,𝐴

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

Proof of Theorem 2rexbidva

Step	Hyp	Ref	Expression
1		2ralbidva.1	. . . 4 ⊢ ((𝜑 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) → (𝜓 ↔ 𝜒))
2	1	anassrs 466	. . 3 ⊢ (((𝜑 ∧ 𝑥 ∈ 𝐴) ∧ 𝑦 ∈ 𝐵) → (𝜓 ↔ 𝜒))
3	2	rexbidva 3174	. 2 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (∃𝑦 ∈ 𝐵 𝜓 ↔ ∃𝑦 ∈ 𝐵 𝜒))
4	3	rexbidva 3174	1 ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜓 ↔ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ 𝐵 𝜒))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 394   ∈ wcel 2104  ∃wrex 3068

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1911

This theorem depends on definitions:  df-bi 206  df-an 395  df-ex 1780  df-rex 3069

This theorem is referenced by:  2reu4lem  4524  wrdl3s3  14917  bezoutlem2  16486  bezoutlem4  16488  vdwmc2  16916  lsmcom2  19564  lsmass  19578  lsmcomx  19765  lsmspsn  20839  hausdiag  23369  imasf1oxms  24218  mulsval  27804  mulscom  27834  addsdi  27849  mulsasslem3  27859  istrkg2ld  27978  iscgra  28327  axeuclid  28488  elwwlks2  29487  elwspths2spth  29488  fusgr2wsp2nb  29854  shscom  30839  lsmssass  32786  sategoelfvb  34708  3dim0  38631  islpln5  38709  islvol5  38753  isline2  38948  isline3  38950  paddcom  38987  cdlemg2cex  39765  prprspr2  46484  pgrpgt2nabl  47130  elbigolo1  47330