Theorem imaeqsexv 7370

Description: Substitute a function value into an existential quantifier over an image. (Contributed by Scott Fenton, 27-Sep-2024.)

Hypothesis

Ref	Expression
imaeqsex.1	⊢ (𝑥 = (𝐹‘𝑦) → (𝜑 ↔ 𝜓))

Assertion

Ref	Expression
imaeqsexv	⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → (∃𝑥 ∈ (𝐹 “ 𝐵)𝜑 ↔ ∃𝑦 ∈ 𝐵 𝜓))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵,𝑦   𝑥,𝐹,𝑦   𝜑,𝑦   𝜓,𝑥

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

Proof of Theorem imaeqsexv

Step	Hyp	Ref	Expression
1		df-rex 3060	. . 3 ⊢ (∃𝑥 ∈ (𝐹 “ 𝐵)𝜑 ↔ ∃𝑥(𝑥 ∈ (𝐹 “ 𝐵) ∧ 𝜑))
2		fvelimab 6970	. . . . 5 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → (𝑥 ∈ (𝐹 “ 𝐵) ↔ ∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥))
3	2	anbi1d 629	. . . 4 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → ((𝑥 ∈ (𝐹 “ 𝐵) ∧ 𝜑) ↔ (∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑)))
4	3	exbidv 1916	. . 3 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → (∃𝑥(𝑥 ∈ (𝐹 “ 𝐵) ∧ 𝜑) ↔ ∃𝑥(∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑)))
5	1, 4	bitrid 282	. 2 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → (∃𝑥 ∈ (𝐹 “ 𝐵)𝜑 ↔ ∃𝑥(∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑)))
6		rexcom4 3275	. . 3 ⊢ (∃𝑦 ∈ 𝐵 ∃𝑥((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ ∃𝑥∃𝑦 ∈ 𝐵 ((𝐹‘𝑦) = 𝑥 ∧ 𝜑))
7		eqcom 2732	. . . . . . 7 ⊢ ((𝐹‘𝑦) = 𝑥 ↔ 𝑥 = (𝐹‘𝑦))
8	7	anbi1i 622	. . . . . 6 ⊢ (((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ (𝑥 = (𝐹‘𝑦) ∧ 𝜑))
9	8	exbii 1842	. . . . 5 ⊢ (∃𝑥((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ ∃𝑥(𝑥 = (𝐹‘𝑦) ∧ 𝜑))
10		fvex 6909	. . . . . 6 ⊢ (𝐹‘𝑦) ∈ V
11		imaeqsex.1	. . . . . 6 ⊢ (𝑥 = (𝐹‘𝑦) → (𝜑 ↔ 𝜓))
12	10, 11	ceqsexv 3514	. . . . 5 ⊢ (∃𝑥(𝑥 = (𝐹‘𝑦) ∧ 𝜑) ↔ 𝜓)
13	9, 12	bitri 274	. . . 4 ⊢ (∃𝑥((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ 𝜓)
14	13	rexbii 3083	. . 3 ⊢ (∃𝑦 ∈ 𝐵 ∃𝑥((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ ∃𝑦 ∈ 𝐵 𝜓)
15		r19.41v 3178	. . . 4 ⊢ (∃𝑦 ∈ 𝐵 ((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ (∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑))
16	15	exbii 1842	. . 3 ⊢ (∃𝑥∃𝑦 ∈ 𝐵 ((𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ ∃𝑥(∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑))
17	6, 14, 16	3bitr3ri 301	. 2 ⊢ (∃𝑥(∃𝑦 ∈ 𝐵 (𝐹‘𝑦) = 𝑥 ∧ 𝜑) ↔ ∃𝑦 ∈ 𝐵 𝜓)
18	5, 17	bitrdi 286	1 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐵 ⊆ 𝐴) → (∃𝑥 ∈ (𝐹 “ 𝐵)𝜑 ↔ ∃𝑦 ∈ 𝐵 𝜓))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 394   = wceq 1533  ∃wex 1773   ∈ wcel 2098  ∃wrex 3059   ⊆ wss 3944   “ cima 5681   Fn wfn 6544  ‘cfv 6549

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-10 2129  ax-11 2146  ax-12 2166  ax-ext 2696  ax-sep 5300  ax-nul 5307  ax-pr 5429

This theorem depends on definitions:  df-bi 206  df-an 395  df-or 846  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-nf 1778  df-sb 2060  df-mo 2528  df-eu 2557  df-clab 2703  df-cleq 2717  df-clel 2802  df-ne 2930  df-ral 3051  df-rex 3060  df-rab 3419  df-v 3463  df-dif 3947  df-un 3949  df-in 3951  df-ss 3961  df-nul 4323  df-if 4531  df-sn 4631  df-pr 4633  df-op 4637  df-uni 4910  df-br 5150  df-opab 5212  df-id 5576  df-xp 5684  df-rel 5685  df-cnv 5686  df-co 5687  df-dm 5688  df-rn 5689  df-res 5690  df-ima 5691  df-iota 6501  df-fun 6551  df-fn 6552  df-fv 6557

This theorem is referenced by:  imaeqsalv  7371  negsid  27999  negsunif  28013