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Theorem caseinj 7429
Description: The "case" construction of two injective relations with disjoint ranges is an injective relation. (Contributed by BJ, 10-Jul-2022.)
Hypotheses
Ref Expression
caseinj.r (𝜑 → Fun 𝑅)
caseinj.s (𝜑 → Fun 𝑆)
caseinj.disj (𝜑 → (ran 𝑅 ∩ ran 𝑆) = ∅)
Assertion
Ref Expression
caseinj (𝜑 → Fun case(𝑅, 𝑆))

Proof of Theorem caseinj
StepHypRef Expression
1 df-inl 7387 . . . . . . 7 inl = (𝑦 ∈ V ↦ ⟨∅, 𝑦⟩)
21funmpt2 5416 . . . . . 6 Fun inl
3 funcnvcnv 5440 . . . . . 6 (Fun inl → Fun inl)
42, 3ax-mp 5 . . . . 5 Fun inl
5 caseinj.r . . . . 5 (𝜑 → Fun 𝑅)
6 funco 5417 . . . . 5 ((Fun inl ∧ Fun 𝑅) → Fun (inl ∘ 𝑅))
74, 5, 6sylancr 418 . . . 4 (𝜑 → Fun (inl ∘ 𝑅))
8 cnvco 4965 . . . . 5 (𝑅inl) = (inl ∘ 𝑅)
98funeqi 5398 . . . 4 (Fun (𝑅inl) ↔ Fun (inl ∘ 𝑅))
107, 9sylibr 134 . . 3 (𝜑 → Fun (𝑅inl))
11 df-inr 7388 . . . . . . 7 inr = (𝑥 ∈ V ↦ ⟨1o, 𝑥⟩)
1211funmpt2 5416 . . . . . 6 Fun inr
13 funcnvcnv 5440 . . . . . 6 (Fun inr → Fun inr)
1412, 13ax-mp 5 . . . . 5 Fun inr
15 caseinj.s . . . . 5 (𝜑 → Fun 𝑆)
16 funco 5417 . . . . 5 ((Fun inr ∧ Fun 𝑆) → Fun (inr ∘ 𝑆))
1714, 15, 16sylancr 418 . . . 4 (𝜑 → Fun (inr ∘ 𝑆))
18 cnvco 4965 . . . . 5 (𝑆inr) = (inr ∘ 𝑆)
1918funeqi 5398 . . . 4 (Fun (𝑆inr) ↔ Fun (inr ∘ 𝑆))
2017, 19sylibr 134 . . 3 (𝜑 → Fun (𝑆inr))
21 df-rn 4785 . . . . . . 7 ran (𝑅inl) = dom (𝑅inl)
22 rncoss 5053 . . . . . . 7 ran (𝑅inl) ⊆ ran 𝑅
2321, 22eqsstrri 3281 . . . . . 6 dom (𝑅inl) ⊆ ran 𝑅
24 df-rn 4785 . . . . . . 7 ran (𝑆inr) = dom (𝑆inr)
25 rncoss 5053 . . . . . . 7 ran (𝑆inr) ⊆ ran 𝑆
2624, 25eqsstrri 3281 . . . . . 6 dom (𝑆inr) ⊆ ran 𝑆
27 ss2in 3459 . . . . . 6 ((dom (𝑅inl) ⊆ ran 𝑅 ∧ dom (𝑆inr) ⊆ ran 𝑆) → (dom (𝑅inl) ∩ dom (𝑆inr)) ⊆ (ran 𝑅 ∩ ran 𝑆))
2823, 26, 27mp2an 430 . . . . 5 (dom (𝑅inl) ∩ dom (𝑆inr)) ⊆ (ran 𝑅 ∩ ran 𝑆)
29 caseinj.disj . . . . 5 (𝜑 → (ran 𝑅 ∩ ran 𝑆) = ∅)
3028, 29sseqtrid 3298 . . . 4 (𝜑 → (dom (𝑅inl) ∩ dom (𝑆inr)) ⊆ ∅)
31 ss0 3563 . . . 4 ((dom (𝑅inl) ∩ dom (𝑆inr)) ⊆ ∅ → (dom (𝑅inl) ∩ dom (𝑆inr)) = ∅)
3230, 31syl 14 . . 3 (𝜑 → (dom (𝑅inl) ∩ dom (𝑆inr)) = ∅)
33 funun 5422 . . 3 (((Fun (𝑅inl) ∧ Fun (𝑆inr)) ∧ (dom (𝑅inl) ∩ dom (𝑆inr)) = ∅) → Fun ((𝑅inl) ∪ (𝑆inr)))
3410, 20, 32, 33syl21anc 1277 . 2 (𝜑 → Fun ((𝑅inl) ∪ (𝑆inr)))
35 df-case 7424 . . . . 5 case(𝑅, 𝑆) = ((𝑅inl) ∪ (𝑆inr))
3635cnveqi 4955 . . . 4 case(𝑅, 𝑆) = ((𝑅inl) ∪ (𝑆inr))
37 cnvun 5193 . . . 4 ((𝑅inl) ∪ (𝑆inr)) = ((𝑅inl) ∪ (𝑆inr))
3836, 37eqtri 2259 . . 3 case(𝑅, 𝑆) = ((𝑅inl) ∪ (𝑆inr))
3938funeqi 5398 . 2 (Fun case(𝑅, 𝑆) ↔ Fun ((𝑅inl) ∪ (𝑆inr)))
4034, 39sylibr 134 1 (𝜑 → Fun case(𝑅, 𝑆))
Colors of variables:    wff set class
This proof depends on syntax axioms:  wi 4   = wceq 1402  Vcvv 2821  cun 3218  cin 3219  wss 3220  c0 3520  cop 3712  ccnv 4773  dom cdm 4774  ran crn 4775  ccom 4778  Fun wfun 5371  1oc1o 6680  inlcinl 7385  inrcinr 7386  casecdjucase 7423
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4249  ax-pow 4311  ax-pr 4346
This proof depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-rex 2534  df-v 2823  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-br 4131  df-opab 4193  df-mpt 4194  df-id 4438  df-xp 4780  df-rel 4781  df-cnv 4782  df-co 4783  df-dm 4784  df-rn 4785  df-fun 5379  df-inl 7387  df-inr 7388  df-case 7424
This theorem is used by:  casef1  7430
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