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Theorem resco 5603
Description: Associative law for the restriction of a composition. (Contributed by NM, 12-Dec-2006.)
Assertion
Ref Expression
resco ((𝐴𝐵) ↾ 𝐶) = (𝐴 ∘ (𝐵𝐶))

Proof of Theorem resco
Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 relres 5390 . 2 Rel ((𝐴𝐵) ↾ 𝐶)
2 relco 5597 . 2 Rel (𝐴 ∘ (𝐵𝐶))
3 vex 3192 . . . . . 6 𝑥 ∈ V
4 vex 3192 . . . . . 6 𝑦 ∈ V
53, 4brco 5257 . . . . 5 (𝑥(𝐴𝐵)𝑦 ↔ ∃𝑧(𝑥𝐵𝑧𝑧𝐴𝑦))
65anbi1i 730 . . . 4 ((𝑥(𝐴𝐵)𝑦𝑥𝐶) ↔ (∃𝑧(𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶))
7 19.41v 1911 . . . 4 (∃𝑧((𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶) ↔ (∃𝑧(𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶))
8 an32 838 . . . . . 6 (((𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶) ↔ ((𝑥𝐵𝑧𝑥𝐶) ∧ 𝑧𝐴𝑦))
9 vex 3192 . . . . . . . 8 𝑧 ∈ V
109brres 5367 . . . . . . 7 (𝑥(𝐵𝐶)𝑧 ↔ (𝑥𝐵𝑧𝑥𝐶))
1110anbi1i 730 . . . . . 6 ((𝑥(𝐵𝐶)𝑧𝑧𝐴𝑦) ↔ ((𝑥𝐵𝑧𝑥𝐶) ∧ 𝑧𝐴𝑦))
128, 11bitr4i 267 . . . . 5 (((𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶) ↔ (𝑥(𝐵𝐶)𝑧𝑧𝐴𝑦))
1312exbii 1771 . . . 4 (∃𝑧((𝑥𝐵𝑧𝑧𝐴𝑦) ∧ 𝑥𝐶) ↔ ∃𝑧(𝑥(𝐵𝐶)𝑧𝑧𝐴𝑦))
146, 7, 133bitr2i 288 . . 3 ((𝑥(𝐴𝐵)𝑦𝑥𝐶) ↔ ∃𝑧(𝑥(𝐵𝐶)𝑧𝑧𝐴𝑦))
154brres 5367 . . 3 (𝑥((𝐴𝐵) ↾ 𝐶)𝑦 ↔ (𝑥(𝐴𝐵)𝑦𝑥𝐶))
163, 4brco 5257 . . 3 (𝑥(𝐴 ∘ (𝐵𝐶))𝑦 ↔ ∃𝑧(𝑥(𝐵𝐶)𝑧𝑧𝐴𝑦))
1714, 15, 163bitr4i 292 . 2 (𝑥((𝐴𝐵) ↾ 𝐶)𝑦𝑥(𝐴 ∘ (𝐵𝐶))𝑦)
181, 2, 17eqbrriv 5181 1 ((𝐴𝐵) ↾ 𝐶) = (𝐴 ∘ (𝐵𝐶))
Colors of variables: wff setvar class
Syntax hints:  wa 384   = wceq 1480  wex 1701  wcel 1987   class class class wbr 4618  cres 5081  ccom 5083
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1719  ax-4 1734  ax-5 1836  ax-6 1885  ax-7 1932  ax-9 1996  ax-10 2016  ax-11 2031  ax-12 2044  ax-13 2245  ax-ext 2601  ax-sep 4746  ax-nul 4754  ax-pr 4872
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1038  df-tru 1483  df-ex 1702  df-nf 1707  df-sb 1878  df-eu 2473  df-mo 2474  df-clab 2608  df-cleq 2614  df-clel 2617  df-nfc 2750  df-ral 2912  df-rex 2913  df-rab 2916  df-v 3191  df-dif 3562  df-un 3564  df-in 3566  df-ss 3573  df-nul 3897  df-if 4064  df-sn 4154  df-pr 4156  df-op 4160  df-br 4619  df-opab 4679  df-xp 5085  df-rel 5086  df-co 5088  df-res 5091
This theorem is referenced by:  cocnvcnv2  5611  coires1  5617  dftpos2  7321  canthp1lem2  9426  o1res  14232  gsumzaddlem  18249  tsmsf1o  21867  tsmsmhm  21868  mbfres  23330  hhssims  27999  erdsze2lem2  30921  cvmlift2lem9a  31020  mbfresfi  33115  cocnv  33179  diophrw  36829  eldioph2  36832  mbfres2cn  39502  funcoressn  40532
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