Theorem mptssid 44242

Description: The mapping operation expressed with its actual domain. (Contributed by Glauco Siliprandi, 23-Oct-2021.)

Hypotheses

Ref	Expression
mptssid.1	⊢ Ⅎ𝑥𝐴
mptssid.2	⊢ 𝐶 = {𝑥 ∈ 𝐴 ∣ 𝐵 ∈ V}

Assertion

Ref	Expression
mptssid	⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐶 ↦ 𝐵)

Proof of Theorem mptssid

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		eqvisset 3490	. . . . . . . 8 ⊢ (𝑦 = 𝐵 → 𝐵 ∈ V)
2	1	anim2i 615	. . . . . . 7 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → (𝑥 ∈ 𝐴 ∧ 𝐵 ∈ V))
3		rabid 3450	. . . . . . 7 ⊢ (𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ∈ V} ↔ (𝑥 ∈ 𝐴 ∧ 𝐵 ∈ V))
4	2, 3	sylibr 233	. . . . . 6 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑥 ∈ {𝑥 ∈ 𝐴 ∣ 𝐵 ∈ V})
5		mptssid.2	. . . . . 6 ⊢ 𝐶 = {𝑥 ∈ 𝐴 ∣ 𝐵 ∈ V}
6	4, 5	eleqtrrdi 2842	. . . . 5 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑥 ∈ 𝐶)
7		simpr 483	. . . . 5 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → 𝑦 = 𝐵)
8	6, 7	jca 510	. . . 4 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) → (𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵))
9		mptssid.1	. . . . . . . 8 ⊢ Ⅎ𝑥𝐴
10	9	ssrab2f 44107	. . . . . . 7 ⊢ {𝑥 ∈ 𝐴 ∣ 𝐵 ∈ V} ⊆ 𝐴
11	5, 10	eqsstri 4015	. . . . . 6 ⊢ 𝐶 ⊆ 𝐴
12	11	sseli 3977	. . . . 5 ⊢ (𝑥 ∈ 𝐶 → 𝑥 ∈ 𝐴)
13	12	anim1i 613	. . . 4 ⊢ ((𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵) → (𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵))
14	8, 13	impbii 208	. . 3 ⊢ ((𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵) ↔ (𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵))
15	14	opabbii 5214	. 2 ⊢ {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵)} = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵)}
16		df-mpt 5231	. 2 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ 𝐴 ∧ 𝑦 = 𝐵)}
17		df-mpt 5231	. 2 ⊢ (𝑥 ∈ 𝐶 ↦ 𝐵) = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ 𝐶 ∧ 𝑦 = 𝐵)}
18	15, 16, 17	3eqtr4i 2768	1 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐶 ↦ 𝐵)

Syntax hints:   ∧ wa 394   = wceq 1539   ∈ wcel 2104  Ⅎwnfc 2881  {crab 3430  Vcvv 3472  {copab 5209   ↦ cmpt 5230

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  ax-6 1969  ax-7 2009  ax-8 2106  ax-9 2114  ax-10 2135  ax-11 2152  ax-12 2169  ax-ext 2701

This theorem depends on definitions:  df-bi 206  df-an 395  df-or 844  df-tru 1542  df-ex 1780  df-nf 1784  df-sb 2066  df-clab 2708  df-cleq 2722  df-clel 2808  df-nfc 2883  df-ral 3060  df-rab 3431  df-v 3474  df-in 3954  df-ss 3964  df-opab 5210  df-mpt 5231

This theorem is referenced by:  limsupequzmpt2  44732  liminfequzmpt2  44805