Theorem bj-opabco 37154

Description: Composition of ordered-pair class abstractions. (Contributed by BJ, 22-May-2024.)

Assertion

Ref	Expression
bj-opabco	⊢ ({⟨𝑦, 𝑧⟩ ∣ 𝜓} ∘ {⟨𝑥, 𝑦⟩ ∣ 𝜑}) = {⟨𝑥, 𝑧⟩ ∣ ∃𝑦(𝜑 ∧ 𝜓)}

Distinct variable groups:   𝑥,𝑦,𝑧   𝜓,𝑥   𝜑,𝑧

Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑦,𝑧)

Proof of Theorem bj-opabco

Dummy variables 𝑎 𝑏 𝑐 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-co 5709	. 2 ⊢ ({⟨𝑦, 𝑧⟩ ∣ 𝜓} ∘ {⟨𝑥, 𝑦⟩ ∣ 𝜑}) = {⟨𝑎, 𝑏⟩ ∣ ∃𝑐(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)}
2		nfcv 2908	. . . . . 6 ⊢ Ⅎ𝑥𝑎
3		nfopab1 5236	. . . . . 6 ⊢ Ⅎ𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}
4		nfcv 2908	. . . . . 6 ⊢ Ⅎ𝑥𝑐
5	2, 3, 4	nfbr 5213	. . . . 5 ⊢ Ⅎ𝑥 𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐
6		nfv 1913	. . . . 5 ⊢ Ⅎ𝑥 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏
7	5, 6	nfan 1898	. . . 4 ⊢ Ⅎ𝑥(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)
8	7	nfex 2328	. . 3 ⊢ Ⅎ𝑥∃𝑐(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)
9		nfv 1913	. . . . 5 ⊢ Ⅎ𝑧 𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐
10		nfcv 2908	. . . . . 6 ⊢ Ⅎ𝑧𝑐
11		nfopab2 5237	. . . . . 6 ⊢ Ⅎ𝑧{⟨𝑦, 𝑧⟩ ∣ 𝜓}
12		nfcv 2908	. . . . . 6 ⊢ Ⅎ𝑧𝑏
13	10, 11, 12	nfbr 5213	. . . . 5 ⊢ Ⅎ𝑧 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏
14	9, 13	nfan 1898	. . . 4 ⊢ Ⅎ𝑧(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)
15	14	nfex 2328	. . 3 ⊢ Ⅎ𝑧∃𝑐(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)
16		nfv 1913	. . 3 ⊢ Ⅎ𝑎∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)
17		nfv 1913	. . 3 ⊢ Ⅎ𝑏∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)
18		nfv 1913	. . . 4 ⊢ Ⅎ𝑦(𝑎 = 𝑥 ∧ 𝑏 = 𝑧)
19		nfcv 2908	. . . . . . 7 ⊢ Ⅎ𝑦𝑎
20		nfopab2 5237	. . . . . . 7 ⊢ Ⅎ𝑦{⟨𝑥, 𝑦⟩ ∣ 𝜑}
21		nfcv 2908	. . . . . . 7 ⊢ Ⅎ𝑦𝑐
22	19, 20, 21	nfbr 5213	. . . . . 6 ⊢ Ⅎ𝑦 𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐
23		nfopab1 5236	. . . . . . 7 ⊢ Ⅎ𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}
24		nfcv 2908	. . . . . . 7 ⊢ Ⅎ𝑦𝑏
25	21, 23, 24	nfbr 5213	. . . . . 6 ⊢ Ⅎ𝑦 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏
26	22, 25	nfan 1898	. . . . 5 ⊢ Ⅎ𝑦(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)
27	26	a1i 11	. . . 4 ⊢ ((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) → Ⅎ𝑦(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏))
28		simpll 766	. . . . . . 7 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → 𝑎 = 𝑥)
29		simpr 484	. . . . . . 7 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → 𝑐 = 𝑦)
30	28, 29	breq12d 5179	. . . . . 6 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → (𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ↔ 𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦))
31		simplr 768	. . . . . . 7 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → 𝑏 = 𝑧)
32	29, 31	breq12d 5179	. . . . . 6 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → (𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏 ↔ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧))
33	30, 32	anbi12d 631	. . . . 5 ⊢ (((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) ∧ 𝑐 = 𝑦) → ((𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏) ↔ (𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)))
34	33	ex 412	. . . 4 ⊢ ((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) → (𝑐 = 𝑦 → ((𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏) ↔ (𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧))))
35	18, 27, 34	cbvexdw 2345	. . 3 ⊢ ((𝑎 = 𝑥 ∧ 𝑏 = 𝑧) → (∃𝑐(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏) ↔ ∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)))
36	8, 15, 16, 17, 35	cbvopab 5238	. 2 ⊢ {⟨𝑎, 𝑏⟩ ∣ ∃𝑐(𝑎{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑐 ∧ 𝑐{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑏)} = {⟨𝑥, 𝑧⟩ ∣ ∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)}
37		bj-opelopabid 37153	. . . . 5 ⊢ (𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ↔ 𝜑)
38		bj-opelopabid 37153	. . . . 5 ⊢ (𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧 ↔ 𝜓)
39	37, 38	anbi12i 627	. . . 4 ⊢ ((𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧) ↔ (𝜑 ∧ 𝜓))
40	39	exbii 1846	. . 3 ⊢ (∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧) ↔ ∃𝑦(𝜑 ∧ 𝜓))
41	40	opabbii 5233	. 2 ⊢ {⟨𝑥, 𝑧⟩ ∣ ∃𝑦(𝑥{⟨𝑥, 𝑦⟩ ∣ 𝜑}𝑦 ∧ 𝑦{⟨𝑦, 𝑧⟩ ∣ 𝜓}𝑧)} = {⟨𝑥, 𝑧⟩ ∣ ∃𝑦(𝜑 ∧ 𝜓)}
42	1, 36, 41	3eqtri 2772	1 ⊢ ({⟨𝑦, 𝑧⟩ ∣ 𝜓} ∘ {⟨𝑥, 𝑦⟩ ∣ 𝜑}) = {⟨𝑥, 𝑧⟩ ∣ ∃𝑦(𝜑 ∧ 𝜓)}

Syntax hints:   ↔ wb 206   ∧ wa 395   = wceq 1537  ∃wex 1777  Ⅎwnf 1781   class class class wbr 5166  {copab 5228   ∘ ccom 5704

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-11 2158  ax-12 2178  ax-ext 2711  ax-sep 5317  ax-nul 5324  ax-pr 5447

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-3an 1089  df-tru 1540  df-fal 1550  df-ex 1778  df-nf 1782  df-sb 2065  df-mo 2543  df-eu 2572  df-clab 2718  df-cleq 2732  df-clel 2819  df-nfc 2895  df-rab 3444  df-v 3490  df-dif 3979  df-un 3981  df-ss 3993  df-nul 4353  df-if 4549  df-sn 4649  df-pr 4651  df-op 4655  df-br 5167  df-opab 5229  df-co 5709

This theorem is referenced by:  bj-imdirco  37156