Theorem unissb 4884

Description: Relationship involving membership, subset, and union. Exercise 5 of [Enderton] p. 26 and its converse. (Contributed by NM, 20-Sep-2003.) Avoid ax-11 2163. (Revised by BTernaryTau, 28-Dec-2024.)

Assertion

Ref	Expression
unissb	⊢ (∪ 𝐴 ⊆ 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵)

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵

Proof of Theorem unissb

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

Step	Hyp	Ref	Expression
1		eluni 4854	. . . . . 6 ⊢ (𝑦 ∈ ∪ 𝐴 ↔ ∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴))
2	1	imbi1i 349	. . . . 5 ⊢ ((𝑦 ∈ ∪ 𝐴 → 𝑦 ∈ 𝐵) ↔ (∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵))
3		19.23v 1944	. . . . 5 ⊢ (∀𝑥((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ (∃𝑥(𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵))
4	2, 3	bitr4i 278	. . . 4 ⊢ ((𝑦 ∈ ∪ 𝐴 → 𝑦 ∈ 𝐵) ↔ ∀𝑥((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵))
5	4	albii 1821	. . 3 ⊢ (∀𝑦(𝑦 ∈ ∪ 𝐴 → 𝑦 ∈ 𝐵) ↔ ∀𝑦∀𝑥((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵))
6		elequ1 2121	. . . . . . 7 ⊢ (𝑦 = 𝑧 → (𝑦 ∈ 𝑥 ↔ 𝑧 ∈ 𝑥))
7	6	anbi1d 632	. . . . . 6 ⊢ (𝑦 = 𝑧 → ((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) ↔ (𝑧 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴)))
8		eleq1w 2820	. . . . . 6 ⊢ (𝑦 = 𝑧 → (𝑦 ∈ 𝐵 ↔ 𝑧 ∈ 𝐵))
9	7, 8	imbi12d 344	. . . . 5 ⊢ (𝑦 = 𝑧 → (((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ((𝑧 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑧 ∈ 𝐵)))
10		elequ2 2129	. . . . . . 7 ⊢ (𝑥 = 𝑧 → (𝑦 ∈ 𝑥 ↔ 𝑦 ∈ 𝑧))
11		eleq1w 2820	. . . . . . 7 ⊢ (𝑥 = 𝑧 → (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴))
12	10, 11	anbi12d 633	. . . . . 6 ⊢ (𝑥 = 𝑧 → ((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) ↔ (𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴)))
13	12	imbi1d 341	. . . . 5 ⊢ (𝑥 = 𝑧 → (((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ((𝑦 ∈ 𝑧 ∧ 𝑧 ∈ 𝐴) → 𝑦 ∈ 𝐵)))
14	9, 13	alcomw 2047	. . . 4 ⊢ (∀𝑦∀𝑥((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ∀𝑥∀𝑦((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵))
15		19.21v 1941	. . . . . 6 ⊢ (∀𝑦(𝑥 ∈ 𝐴 → (𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)) ↔ (𝑥 ∈ 𝐴 → ∀𝑦(𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)))
16		impexp 450	. . . . . . . 8 ⊢ (((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ (𝑦 ∈ 𝑥 → (𝑥 ∈ 𝐴 → 𝑦 ∈ 𝐵)))
17		bi2.04 387	. . . . . . . 8 ⊢ ((𝑦 ∈ 𝑥 → (𝑥 ∈ 𝐴 → 𝑦 ∈ 𝐵)) ↔ (𝑥 ∈ 𝐴 → (𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)))
18	16, 17	bitri 275	. . . . . . 7 ⊢ (((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ (𝑥 ∈ 𝐴 → (𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)))
19	18	albii 1821	. . . . . 6 ⊢ (∀𝑦((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ∀𝑦(𝑥 ∈ 𝐴 → (𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)))
20		df-ss 3907	. . . . . . 7 ⊢ (𝑥 ⊆ 𝐵 ↔ ∀𝑦(𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵))
21	20	imbi2i 336	. . . . . 6 ⊢ ((𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵) ↔ (𝑥 ∈ 𝐴 → ∀𝑦(𝑦 ∈ 𝑥 → 𝑦 ∈ 𝐵)))
22	15, 19, 21	3bitr4i 303	. . . . 5 ⊢ (∀𝑦((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ (𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵))
23	22	albii 1821	. . . 4 ⊢ (∀𝑥∀𝑦((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵))
24	14, 23	bitri 275	. . 3 ⊢ (∀𝑦∀𝑥((𝑦 ∈ 𝑥 ∧ 𝑥 ∈ 𝐴) → 𝑦 ∈ 𝐵) ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵))
25	5, 24	bitri 275	. 2 ⊢ (∀𝑦(𝑦 ∈ ∪ 𝐴 → 𝑦 ∈ 𝐵) ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵))
26		df-ss 3907	. 2 ⊢ (∪ 𝐴 ⊆ 𝐵 ↔ ∀𝑦(𝑦 ∈ ∪ 𝐴 → 𝑦 ∈ 𝐵))
27		df-ral 3053	. 2 ⊢ (∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝑥 ⊆ 𝐵))
28	25, 26, 27	3bitr4i 303	1 ⊢ (∪ 𝐴 ⊆ 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝑥 ⊆ 𝐵)

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395  ∀wal 1540  ∃wex 1781   ∈ wcel 2114  ∀wral 3052   ⊆ wss 3890  ∪ cuni 4851

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-ext 2709

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1545  df-ex 1782  df-sb 2069  df-clab 2716  df-cleq 2729  df-clel 2812  df-ral 3053  df-v 3432  df-ss 3907  df-uni 4852

This theorem is referenced by:  uniss2  4885  ssunieq  4887  sspwuni  5043  pwssb  5044  ordunisssuc  6425  sorpssuni  7679  uniordint  7748  sbthlem1  9018  ordunifi  9193  isfinite2  9201  cflim2  10176  fin23lem16  10248  fin23lem29  10254  fin1a2lem11  10323  fin1a2lem13  10325  itunitc  10334  zorng  10417  wuncval2  10661  suplem1pr  10966  suplem2pr  10967  mrcuni  17578  ipodrsfi  18496  mrelatlub  18519  subgint  19117  efgval  19683  toponmre  23068  neips  23088  neiuni  23097  alexsubALTlem2  24023  alexsubALTlem3  24024  tgpconncompeqg  24087  unidmvol  25518  oldf  27843  tglnunirn  28630  uniinn0  32635  elrspunidl  33503  ssdifidllem  33531  ssmxidllem  33548  locfinreflem  34000  zarclsiin  34031  zarclsint  34032  zarcmplem  34041  sxbrsigalem0  34431  dya2iocuni  34443  dya2iocucvr  34444  carsguni  34468  topjoin  36563  fnejoin1  36566  fnejoin2  36567  ovoliunnfl  37997  voliunnfl  37999  volsupnfl  38000  intidl  38364  unichnidl  38366  onuniintrab  43672  onsupmaxb  43685  onsupnub  43695  mnuunid  44722  expanduniss  44738  salexct  46780  unilbss  49305  unilbeu  49472  ipolublem  49473  setrec1lem2  50175  setrec2fun  50179