Theorem glbfun 16816

Description: The GLB is a function. (Contributed by NM, 9-Sep-2018.)

Hypothesis

Ref	Expression
glbfun.g	⊢ 𝐺 = (glb‘𝐾)

Assertion

Ref	Expression
glbfun	⊢ Fun 𝐺

Proof of Theorem glbfun

Dummy variables 𝑥 𝑠 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		funmpt 5840	. . . 4 ⊢ Fun (𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))))
2		funres 5843	. . . 4 ⊢ (Fun (𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))) → Fun ((𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))) ↾ {𝑠 ∣ ∃!𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))}))
3	1, 2	ax-mp 5	. . 3 ⊢ Fun ((𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))) ↾ {𝑠 ∣ ∃!𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))})
4		eqid 2610	. . . . 5 ⊢ (Base‘𝐾) = (Base‘𝐾)
5		eqid 2610	. . . . 5 ⊢ (le‘𝐾) = (le‘𝐾)
6		glbfun.g	. . . . 5 ⊢ 𝐺 = (glb‘𝐾)
7		biid 250	. . . . 5 ⊢ ((∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)) ↔ (∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))
8		id 22	. . . . 5 ⊢ (𝐾 ∈ V → 𝐾 ∈ V)
9	4, 5, 6, 7, 8	glbfval 16814	. . . 4 ⊢ (𝐾 ∈ V → 𝐺 = ((𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))) ↾ {𝑠 ∣ ∃!𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))}))
10	9	funeqd 5825	. . 3 ⊢ (𝐾 ∈ V → (Fun 𝐺 ↔ Fun ((𝑠 ∈ 𝒫 (Base‘𝐾) ↦ (℩𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))) ↾ {𝑠 ∣ ∃!𝑥 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ (Base‘𝐾)(∀𝑦 ∈ 𝑠 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))})))
11	3, 10	mpbiri 247	. 2 ⊢ (𝐾 ∈ V → Fun 𝐺)
12		fun0 5868	. . 3 ⊢ Fun ∅
13		fvprc 6097	. . . . 5 ⊢ (¬ 𝐾 ∈ V → (glb‘𝐾) = ∅)
14	6, 13	syl5eq 2656	. . . 4 ⊢ (¬ 𝐾 ∈ V → 𝐺 = ∅)
15	14	funeqd 5825	. . 3 ⊢ (¬ 𝐾 ∈ V → (Fun 𝐺 ↔ Fun ∅))
16	12, 15	mpbiri 247	. 2 ⊢ (¬ 𝐾 ∈ V → Fun 𝐺)
17	11, 16	pm2.61i 175	1 ⊢ Fun 𝐺

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 383   = wceq 1475   ∈ wcel 1977  {cab 2596  ∀wral 2896  ∃!wreu 2898  Vcvv 3173  ∅c0 3874  𝒫 cpw 4108   class class class wbr 4583   ↦ cmpt 4643   ↾ cres 5040  Fun wfun 5798  ‘cfv 5804  ℩crio 6510  Basecbs 15695  lecple 15775  glbcglb 16766

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-rep 4699  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-ral 2901  df-rex 2902  df-reu 2903  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-iun 4457  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-riota 6511  df-glb 16798

This theorem is referenced by:  meetfval  16838  meetfval2  16839