Theorem glbcl 17602

Description: The least upper bound function value belongs to the base set. (Contributed by NM, 7-Sep-2018.)

Hypotheses

Ref	Expression
glbc.b	⊢ 𝐵 = (Base‘𝐾)
glbc.g	⊢ 𝐺 = (glb‘𝐾)
glbc.k	⊢ (𝜑 → 𝐾 ∈ 𝑉)
glbc.s	⊢ (𝜑 → 𝑆 ∈ dom 𝐺)

Assertion

Ref	Expression
glbcl	⊢ (𝜑 → (𝐺‘𝑆) ∈ 𝐵)

Proof of Theorem glbcl

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

Step	Hyp	Ref	Expression
1		glbc.b	. . 3 ⊢ 𝐵 = (Base‘𝐾)
2		eqid 2821	. . 3 ⊢ (le‘𝐾) = (le‘𝐾)
3		glbc.g	. . 3 ⊢ 𝐺 = (glb‘𝐾)
4		biid 263	. . 3 ⊢ ((∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)) ↔ (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))
5		glbc.k	. . 3 ⊢ (𝜑 → 𝐾 ∈ 𝑉)
6		glbc.s	. . . 4 ⊢ (𝜑 → 𝑆 ∈ dom 𝐺)
7	1, 2, 3, 5, 6	glbelss 17599	. . 3 ⊢ (𝜑 → 𝑆 ⊆ 𝐵)
8	1, 2, 3, 4, 5, 7	glbval 17601	. 2 ⊢ (𝜑 → (𝐺‘𝑆) = (℩𝑥 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))))
9	1, 2, 3, 4, 5, 6	glbeu 17600	. . 3 ⊢ (𝜑 → ∃!𝑥 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)))
10		riotacl 7125	. . 3 ⊢ (∃!𝑥 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥)) → (℩𝑥 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))) ∈ 𝐵)
11	9, 10	syl 17	. 2 ⊢ (𝜑 → (℩𝑥 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑥(le‘𝐾)𝑦 ∧ ∀𝑧 ∈ 𝐵 (∀𝑦 ∈ 𝑆 𝑧(le‘𝐾)𝑦 → 𝑧(le‘𝐾)𝑥))) ∈ 𝐵)
12	8, 11	eqeltrd 2913	1 ⊢ (𝜑 → (𝐺‘𝑆) ∈ 𝐵)

Syntax hints:   → wi 4   ∧ wa 398   = wceq 1533   ∈ wcel 2110  ∀wral 3138  ∃!wreu 3140   class class class wbr 5059  dom cdm 5550  ‘cfv 6350  ℩crio 7107  Basecbs 16477  lecple 16566  glbcglb 17547

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1907  ax-6 1966  ax-7 2011  ax-8 2112  ax-9 2120  ax-10 2141  ax-11 2156  ax-12 2172  ax-ext 2793  ax-rep 5183  ax-sep 5196  ax-nul 5203  ax-pow 5259  ax-pr 5322

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3an 1085  df-tru 1536  df-ex 1777  df-nf 1781  df-sb 2066  df-mo 2618  df-eu 2650  df-clab 2800  df-cleq 2814  df-clel 2893  df-nfc 2963  df-ne 3017  df-ral 3143  df-rex 3144  df-reu 3145  df-rab 3147  df-v 3497  df-sbc 3773  df-csb 3884  df-dif 3939  df-un 3941  df-in 3943  df-ss 3952  df-nul 4292  df-if 4468  df-pw 4541  df-sn 4562  df-pr 4564  df-op 4568  df-uni 4833  df-iun 4914  df-br 5060  df-opab 5122  df-mpt 5140  df-id 5455  df-xp 5556  df-rel 5557  df-cnv 5558  df-co 5559  df-dm 5560  df-rn 5561  df-res 5562  df-ima 5563  df-iota 6309  df-fun 6352  df-fn 6353  df-f 6354  df-f1 6355  df-fo 6356  df-f1o 6357  df-fv 6358  df-riota 7108  df-glb 17579

This theorem is referenced by:  glbprop  17603  meetcl  17624  clatlem  17715  op0cl  36314  atl0cl  36433