Theorem smfpimltmpt 47196

Description: Given a function measurable w.r.t. to a sigma-algebra, the preimage of an open interval unbounded below is in the subspace sigma-algebra induced by its domain. (Contributed by Glauco Siliprandi, 26-Jun-2021.)

Hypotheses

Ref	Expression
smfpimltmpt.x	⊢ Ⅎ𝑥𝜑
smfpimltmpt.s	⊢ (𝜑 → 𝑆 ∈ SAlg)
smfpimltmpt.b	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑉)
smfpimltmpt.f	⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ (SMblFn‘𝑆))
smfpimltmpt.r	⊢ (𝜑 → 𝑅 ∈ ℝ)

Assertion

Ref	Expression
smfpimltmpt	⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅} ∈ (𝑆 ↾t 𝐴))

Distinct variable groups:   𝑥,𝐴   𝑥,𝑅

Allowed substitution hints:   𝜑(𝑥)   𝐵(𝑥)   𝑆(𝑥)   𝑉(𝑥)

Proof of Theorem smfpimltmpt

Step	Hyp	Ref	Expression
1		nfmpt1 5178	. . 3 ⊢ Ⅎ𝑥(𝑥 ∈ 𝐴 ↦ 𝐵)
2		smfpimltmpt.s	. . 3 ⊢ (𝜑 → 𝑆 ∈ SAlg)
3		smfpimltmpt.f	. . 3 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) ∈ (SMblFn‘𝑆))
4		eqid 2740	. . 3 ⊢ dom (𝑥 ∈ 𝐴 ↦ 𝐵) = dom (𝑥 ∈ 𝐴 ↦ 𝐵)
5		smfpimltmpt.r	. . 3 ⊢ (𝜑 → 𝑅 ∈ ℝ)
6	1, 2, 3, 4, 5	smfpreimaltf 47186	. 2 ⊢ (𝜑 → {𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵) ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅} ∈ (𝑆 ↾t dom (𝑥 ∈ 𝐴 ↦ 𝐵)))
7		smfpimltmpt.x	. . . . . 6 ⊢ Ⅎ𝑥𝜑
8		eqid 2740	. . . . . 6 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵)
9		smfpimltmpt.b	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ 𝑉)
10	7, 8, 9	dmmptdf 45676	. . . . 5 ⊢ (𝜑 → dom (𝑥 ∈ 𝐴 ↦ 𝐵) = 𝐴)
11	1	nfdm 5900	. . . . . 6 ⊢ Ⅎ𝑥dom (𝑥 ∈ 𝐴 ↦ 𝐵)
12		nfcv 2902	. . . . . 6 ⊢ Ⅎ𝑥𝐴
13	11, 12	rabeqf 3426	. . . . 5 ⊢ (dom (𝑥 ∈ 𝐴 ↦ 𝐵) = 𝐴 → {𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵) ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅} = {𝑥 ∈ 𝐴 ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅})
14	10, 13	syl 17	. . . 4 ⊢ (𝜑 → {𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵) ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅} = {𝑥 ∈ 𝐴 ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅})
15	8	a1i 11	. . . . . . 7 ⊢ (𝜑 → (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵))
16	15, 9	fvmpt2d 6956	. . . . . 6 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) = 𝐵)
17	16	breq1d 5089	. . . . 5 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅 ↔ 𝐵 < 𝑅))
18	7, 17	rabbida 3418	. . . 4 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅} = {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅})
19		eqidd 2741	. . . 4 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅} = {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅})
20	14, 18, 19	3eqtrrd 2780	. . 3 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅} = {𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵) ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅})
21	10	eqcomd 2746	. . . 4 ⊢ (𝜑 → 𝐴 = dom (𝑥 ∈ 𝐴 ↦ 𝐵))
22	21	oveq2d 7379	. . 3 ⊢ (𝜑 → (𝑆 ↾t 𝐴) = (𝑆 ↾t dom (𝑥 ∈ 𝐴 ↦ 𝐵)))
23	20, 22	eleq12d 2834	. 2 ⊢ (𝜑 → ({𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅} ∈ (𝑆 ↾t 𝐴) ↔ {𝑥 ∈ dom (𝑥 ∈ 𝐴 ↦ 𝐵) ∣ ((𝑥 ∈ 𝐴 ↦ 𝐵)‘𝑥) < 𝑅} ∈ (𝑆 ↾t dom (𝑥 ∈ 𝐴 ↦ 𝐵))))
24	6, 23	mpbird 258	1 ⊢ (𝜑 → {𝑥 ∈ 𝐴 ∣ 𝐵 < 𝑅} ∈ (𝑆 ↾t 𝐴))

Syntax hints:   → wi 4   ∧ wa 396   = wceq 1547  Ⅎwnf 1790   ∈ wcel 2119  {crab 3392   class class class wbr 5079   ↦ cmpt 5160  dom cdm 5625  ‘cfv 6492  (class class class)co 7363  ℝcr 11035   < clt 11177   ↾_t crest 17381  SAlgcsalg 46758  SMblFncsmblfn 47145

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-10 2152  ax-11 2168  ax-12 2189  ax-ext 2712  ax-sep 5225  ax-nul 5235  ax-pow 5301  ax-pr 5369  ax-un 7685  ax-cnex 11092  ax-resscn 11093  ax-pre-lttri 11110  ax-pre-lttrn 11111

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3or 1093  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-nf 1791  df-sb 2074  df-mo 2543  df-eu 2573  df-clab 2719  df-cleq 2732  df-clel 2815  df-nfc 2889  df-ne 2936  df-nel 3040  df-ral 3055  df-rex 3065  df-rab 3393  df-v 3434  df-sbc 3731  df-csb 3839  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-nul 4269  df-if 4462  df-pw 4538  df-sn 4563  df-pr 4565  df-op 4569  df-uni 4846  df-iun 4930  df-br 5080  df-opab 5142  df-mpt 5161  df-id 5520  df-po 5533  df-so 5534  df-xp 5631  df-rel 5632  df-cnv 5633  df-co 5634  df-dm 5635  df-rn 5636  df-res 5637  df-ima 5638  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-f1 6497  df-fo 6498  df-f1o 6499  df-fv 6500  df-ov 7366  df-oprab 7367  df-mpo 7368  df-1st 7938  df-2nd 7939  df-er 8640  df-pm 8773  df-en 8891  df-dom 8892  df-sdom 8893  df-pnf 11179  df-mnf 11180  df-xr 11181  df-ltxr 11182  df-le 11183  df-ioo 13300  df-ico 13302  df-smblfn 47146

This theorem is referenced by:  smfaddlem2  47214  smfrec  47239