Theorem itg2l 25655

Description: Elementhood in the set 𝐿 of lower sums of the integral. (Contributed by Mario Carneiro, 28-Jun-2014.)

Hypothesis

Ref	Expression
itg2val.1	⊢ 𝐿 = {𝑥 ∣ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔))}

Assertion

Ref	Expression
itg2l	⊢ (𝐴 ∈ 𝐿 ↔ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)))

Distinct variable groups:   𝑥,𝑔,𝐴   𝑔,𝐹,𝑥

Allowed substitution hints:   𝐿(𝑥,𝑔)

Proof of Theorem itg2l

Step	Hyp	Ref	Expression
1		itg2val.1	. . 3 ⊢ 𝐿 = {𝑥 ∣ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔))}
2	1	eleq2i 2823	. 2 ⊢ (𝐴 ∈ 𝐿 ↔ 𝐴 ∈ {𝑥 ∣ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔))})
3		simpr 484	. . . . 5 ⊢ ((𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)) → 𝐴 = (∫1‘𝑔))
4		fvex 6835	. . . . 5 ⊢ (∫1‘𝑔) ∈ V
5	3, 4	eqeltrdi 2839	. . . 4 ⊢ ((𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)) → 𝐴 ∈ V)
6	5	rexlimivw 3129	. . 3 ⊢ (∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)) → 𝐴 ∈ V)
7		eqeq1 2735	. . . . 5 ⊢ (𝑥 = 𝐴 → (𝑥 = (∫1‘𝑔) ↔ 𝐴 = (∫1‘𝑔)))
8	7	anbi2d 630	. . . 4 ⊢ (𝑥 = 𝐴 → ((𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔)) ↔ (𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔))))
9	8	rexbidv 3156	. . 3 ⊢ (𝑥 = 𝐴 → (∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔)) ↔ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔))))
10	6, 9	elab3 3642	. 2 ⊢ (𝐴 ∈ {𝑥 ∣ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝑥 = (∫1‘𝑔))} ↔ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)))
11	2, 10	bitri 275	1 ⊢ (𝐴 ∈ 𝐿 ↔ ∃𝑔 ∈ dom ∫1(𝑔 ∘r ≤ 𝐹 ∧ 𝐴 = (∫1‘𝑔)))

Syntax hints:   ↔ wb 206   ∧ wa 395   = wceq 1541   ∈ wcel 2111  {cab 2709  ∃wrex 3056  Vcvv 3436   class class class wbr 5091  dom cdm 5616  ‘cfv 6481   ∘_r cofr 7609   ≤ cle 11144  ∫₁citg1 25541

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1968  ax-7 2009  ax-8 2113  ax-9 2121  ax-ext 2703  ax-nul 5244

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-tru 1544  df-fal 1554  df-ex 1781  df-sb 2068  df-clab 2710  df-cleq 2723  df-clel 2806  df-ne 2929  df-rex 3057  df-v 3438  df-dif 3905  df-un 3907  df-ss 3919  df-nul 4284  df-sn 4577  df-pr 4579  df-uni 4860  df-iota 6437  df-fv 6489

This theorem is referenced by:  itg2lr  25656