Theorem divsfval 12911

Description: Value of the function in qusval 12906. (Contributed by Mario Carneiro, 24-Feb-2015.) (Revised by Mario Carneiro, 12-Aug-2015.) (Revised by AV, 12-Jul-2024.)

Hypotheses

Ref	Expression
ercpbl.r	⊢ (𝜑 → ∼ Er 𝑉)
ercpbl.v	⊢ (𝜑 → 𝑉 ∈ 𝑊)
ercpbl.f	⊢ 𝐹 = (𝑥 ∈ 𝑉 ↦ [𝑥] ∼ )

Assertion

Ref	Expression
divsfval	⊢ (𝜑 → (𝐹‘𝐴) = [𝐴] ∼ )

Distinct variable groups:   𝑥, ∼   𝑥,𝐴   𝑥,𝑉   𝜑,𝑥

Allowed substitution hints:   𝐹(𝑥)   𝑊(𝑥)

Proof of Theorem divsfval

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		ercpbl.f	. . . . 5 ⊢ 𝐹 = (𝑥 ∈ 𝑉 ↦ [𝑥] ∼ )
2	1	mptrcl 5640	. . . 4 ⊢ (𝑦 ∈ (𝐹‘𝐴) → 𝐴 ∈ 𝑉)
3	2	a1i 9	. . 3 ⊢ (𝜑 → (𝑦 ∈ (𝐹‘𝐴) → 𝐴 ∈ 𝑉))
4		19.8a 1601	. . . 4 ⊢ (𝑦 ∈ [𝐴] ∼ → ∃𝑦 𝑦 ∈ [𝐴] ∼ )
5		ecdmn0m 6631	. . . . . 6 ⊢ (𝐴 ∈ dom ∼ ↔ ∃𝑦 𝑦 ∈ [𝐴] ∼ )
6	5	biimpri 133	. . . . 5 ⊢ (∃𝑦 𝑦 ∈ [𝐴] ∼ → 𝐴 ∈ dom ∼ )
7		ercpbl.r	. . . . . . 7 ⊢ (𝜑 → ∼ Er 𝑉)
8		erdm 6597	. . . . . . 7 ⊢ ( ∼ Er 𝑉 → dom ∼ = 𝑉)
9	7, 8	syl 14	. . . . . 6 ⊢ (𝜑 → dom ∼ = 𝑉)
10	9	eleq2d 2263	. . . . 5 ⊢ (𝜑 → (𝐴 ∈ dom ∼ ↔ 𝐴 ∈ 𝑉))
11	6, 10	imbitrid 154	. . . 4 ⊢ (𝜑 → (∃𝑦 𝑦 ∈ [𝐴] ∼ → 𝐴 ∈ 𝑉))
12	4, 11	syl5 32	. . 3 ⊢ (𝜑 → (𝑦 ∈ [𝐴] ∼ → 𝐴 ∈ 𝑉))
13		eceq1 6622	. . . . . 6 ⊢ (𝑥 = 𝐴 → [𝑥] ∼ = [𝐴] ∼ )
14		simpr 110	. . . . . 6 ⊢ ((𝜑 ∧ 𝐴 ∈ 𝑉) → 𝐴 ∈ 𝑉)
15		ercpbl.v	. . . . . . . 8 ⊢ (𝜑 → 𝑉 ∈ 𝑊)
16	7	ecss 6630	. . . . . . . 8 ⊢ (𝜑 → [𝐴] ∼ ⊆ 𝑉)
17	15, 16	ssexd 4169	. . . . . . 7 ⊢ (𝜑 → [𝐴] ∼ ∈ V)
18	17	adantr 276	. . . . . 6 ⊢ ((𝜑 ∧ 𝐴 ∈ 𝑉) → [𝐴] ∼ ∈ V)
19	1, 13, 14, 18	fvmptd3 5651	. . . . 5 ⊢ ((𝜑 ∧ 𝐴 ∈ 𝑉) → (𝐹‘𝐴) = [𝐴] ∼ )
20	19	eleq2d 2263	. . . 4 ⊢ ((𝜑 ∧ 𝐴 ∈ 𝑉) → (𝑦 ∈ (𝐹‘𝐴) ↔ 𝑦 ∈ [𝐴] ∼ ))
21	20	ex 115	. . 3 ⊢ (𝜑 → (𝐴 ∈ 𝑉 → (𝑦 ∈ (𝐹‘𝐴) ↔ 𝑦 ∈ [𝐴] ∼ )))
22	3, 12, 21	pm5.21ndd 706	. 2 ⊢ (𝜑 → (𝑦 ∈ (𝐹‘𝐴) ↔ 𝑦 ∈ [𝐴] ∼ ))
23	22	eqrdv 2191	1 ⊢ (𝜑 → (𝐹‘𝐴) = [𝐴] ∼ )

Syntax hints:   → wi 4   ∧ wa 104   ↔ wb 105   = wceq 1364  ∃wex 1503   ∈ wcel 2164  Vcvv 2760   ↦ cmpt 4090  dom cdm 4659  ‘cfv 5254   Er wer 6584  [cec 6585

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-14 2167  ax-ext 2175  ax-sep 4147  ax-pow 4203  ax-pr 4238

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1472  df-sb 1774  df-eu 2045  df-mo 2046  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ral 2477  df-rex 2478  df-rab 2481  df-v 2762  df-sbc 2986  df-csb 3081  df-un 3157  df-in 3159  df-ss 3166  df-pw 3603  df-sn 3624  df-pr 3625  df-op 3627  df-uni 3836  df-br 4030  df-opab 4091  df-mpt 4092  df-id 4324  df-xp 4665  df-rel 4666  df-cnv 4667  df-co 4668  df-dm 4669  df-rn 4670  df-res 4671  df-ima 4672  df-iota 5215  df-fun 5256  df-fv 5262  df-er 6587  df-ec 6589

This theorem is referenced by:  qusrhm  14024