Theorem disjdsct 28863

Description: A disjoint collection is distinct, i.e. each set in this collection is different of all others, provided that it does not contain the empty set This can be expressed as "the converse of the mapping function is a function", or "the mapping function is single-rooted". (Cf. funcnv 5872) (Contributed by Thierry Arnoux, 28-Feb-2017.)

Hypotheses

Ref	Expression
disjdsct.0	⊢ Ⅎ𝑥𝜑
disjdsct.1	⊢ Ⅎ𝑥𝐴
disjdsct.2	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ (𝑉 ∖ {∅}))
disjdsct.3	⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 𝐵)

Assertion

Ref	Expression
disjdsct	⊢ (𝜑 → Fun ◡(𝑥 ∈ 𝐴 ↦ 𝐵))

Distinct variable group:   𝑥,𝑉

Allowed substitution hints:   𝜑(𝑥)   𝐴(𝑥)   𝐵(𝑥)

Proof of Theorem disjdsct

Dummy variables 𝑖 𝑗 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		disjdsct.3	. . . . . . . 8 ⊢ (𝜑 → Disj 𝑥 ∈ 𝐴 𝐵)
2		disjdsct.1	. . . . . . . . 9 ⊢ Ⅎ𝑥𝐴
3	2	disjorsf 28775	. . . . . . . 8 ⊢ (Disj 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
4	1, 3	sylib 207	. . . . . . 7 ⊢ (𝜑 → ∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
5	4	r19.21bi 2916	. . . . . 6 ⊢ ((𝜑 ∧ 𝑖 ∈ 𝐴) → ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
6	5	r19.21bi 2916	. . . . 5 ⊢ (((𝜑 ∧ 𝑖 ∈ 𝐴) ∧ 𝑗 ∈ 𝐴) → (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
7		simpr3 1062	. . . . . . . . 9 ⊢ ((𝜑 ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ 𝐴 ∧ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) → (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)
8		disjdsct.2	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ∈ (𝑉 ∖ {∅}))
9		eldifsni 4261	. . . . . . . . . . . . 13 ⊢ (𝐵 ∈ (𝑉 ∖ {∅}) → 𝐵 ≠ ∅)
10	8, 9	syl 17	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝐵 ≠ ∅)
11	10	sbimi 1873	. . . . . . . . . . 11 ⊢ ([𝑖 / 𝑥](𝜑 ∧ 𝑥 ∈ 𝐴) → [𝑖 / 𝑥]𝐵 ≠ ∅)
12		sban 2387	. . . . . . . . . . . 12 ⊢ ([𝑖 / 𝑥](𝜑 ∧ 𝑥 ∈ 𝐴) ↔ ([𝑖 / 𝑥]𝜑 ∧ [𝑖 / 𝑥]𝑥 ∈ 𝐴))
13		disjdsct.0	. . . . . . . . . . . . . 14 ⊢ Ⅎ𝑥𝜑
14	13	sbf 2368	. . . . . . . . . . . . 13 ⊢ ([𝑖 / 𝑥]𝜑 ↔ 𝜑)
15	2	clelsb3f 28704	. . . . . . . . . . . . 13 ⊢ ([𝑖 / 𝑥]𝑥 ∈ 𝐴 ↔ 𝑖 ∈ 𝐴)
16	14, 15	anbi12i 729	. . . . . . . . . . . 12 ⊢ (([𝑖 / 𝑥]𝜑 ∧ [𝑖 / 𝑥]𝑥 ∈ 𝐴) ↔ (𝜑 ∧ 𝑖 ∈ 𝐴))
17	12, 16	bitri 263	. . . . . . . . . . 11 ⊢ ([𝑖 / 𝑥](𝜑 ∧ 𝑥 ∈ 𝐴) ↔ (𝜑 ∧ 𝑖 ∈ 𝐴))
18		sbsbc 3406	. . . . . . . . . . . 12 ⊢ ([𝑖 / 𝑥]𝐵 ≠ ∅ ↔ [𝑖 / 𝑥]𝐵 ≠ ∅)
19		sbcne12 3938	. . . . . . . . . . . 12 ⊢ ([𝑖 / 𝑥]𝐵 ≠ ∅ ↔ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑖 / 𝑥⦌∅)
20		csb0 3934	. . . . . . . . . . . . 13 ⊢ ⦋𝑖 / 𝑥⦌∅ = ∅
21	20	neeq2i 2847	. . . . . . . . . . . 12 ⊢ (⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑖 / 𝑥⦌∅ ↔ ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅)
22	18, 19, 21	3bitri 285	. . . . . . . . . . 11 ⊢ ([𝑖 / 𝑥]𝐵 ≠ ∅ ↔ ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅)
23	11, 17, 22	3imtr3i 279	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑖 ∈ 𝐴) → ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅)
24	23	3ad2antr1 1219	. . . . . . . . 9 ⊢ ((𝜑 ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ 𝐴 ∧ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) → ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅)
25		disj3 3973	. . . . . . . . . . . . 13 ⊢ ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ ⦋𝑖 / 𝑥⦌𝐵 = (⦋𝑖 / 𝑥⦌𝐵 ∖ ⦋𝑗 / 𝑥⦌𝐵))
26	25	biimpi 205	. . . . . . . . . . . 12 ⊢ ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ → ⦋𝑖 / 𝑥⦌𝐵 = (⦋𝑖 / 𝑥⦌𝐵 ∖ ⦋𝑗 / 𝑥⦌𝐵))
27	26	neeq1d 2841	. . . . . . . . . . 11 ⊢ ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ → (⦋𝑖 / 𝑥⦌𝐵 ≠ ∅ ↔ (⦋𝑖 / 𝑥⦌𝐵 ∖ ⦋𝑗 / 𝑥⦌𝐵) ≠ ∅))
28	27	biimpa 500	. . . . . . . . . 10 ⊢ (((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∧ ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅) → (⦋𝑖 / 𝑥⦌𝐵 ∖ ⦋𝑗 / 𝑥⦌𝐵) ≠ ∅)
29		difn0 3897	. . . . . . . . . 10 ⊢ ((⦋𝑖 / 𝑥⦌𝐵 ∖ ⦋𝑗 / 𝑥⦌𝐵) ≠ ∅ → ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)
30	28, 29	syl 17	. . . . . . . . 9 ⊢ (((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∧ ⦋𝑖 / 𝑥⦌𝐵 ≠ ∅) → ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)
31	7, 24, 30	syl2anc 691	. . . . . . . 8 ⊢ ((𝜑 ∧ (𝑖 ∈ 𝐴 ∧ 𝑗 ∈ 𝐴 ∧ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) → ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)
32	31	3anassrs 1282	. . . . . . 7 ⊢ ((((𝜑 ∧ 𝑖 ∈ 𝐴) ∧ 𝑗 ∈ 𝐴) ∧ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) → ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)
33	32	ex 449	. . . . . 6 ⊢ (((𝜑 ∧ 𝑖 ∈ 𝐴) ∧ 𝑗 ∈ 𝐴) → ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ → ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵))
34	33	orim2d 881	. . . . 5 ⊢ (((𝜑 ∧ 𝑖 ∈ 𝐴) ∧ 𝑗 ∈ 𝐴) → ((𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) → (𝑖 = 𝑗 ∨ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)))
35	6, 34	mpd 15	. . . 4 ⊢ (((𝜑 ∧ 𝑖 ∈ 𝐴) ∧ 𝑗 ∈ 𝐴) → (𝑖 = 𝑗 ∨ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵))
36	35	ralrimiva 2949	. . 3 ⊢ ((𝜑 ∧ 𝑖 ∈ 𝐴) → ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵))
37	36	ralrimiva 2949	. 2 ⊢ (𝜑 → ∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵))
38		nfmpt1 4675	. . 3 ⊢ Ⅎ𝑥(𝑥 ∈ 𝐴 ↦ 𝐵)
39		eqid 2610	. . 3 ⊢ (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑥 ∈ 𝐴 ↦ 𝐵)
40	13, 2, 38, 39, 8	funcnv4mpt 28853	. 2 ⊢ (𝜑 → (Fun ◡(𝑥 ∈ 𝐴 ↦ 𝐵) ↔ ∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ ⦋𝑖 / 𝑥⦌𝐵 ≠ ⦋𝑗 / 𝑥⦌𝐵)))
41	37, 40	mpbird 246	1 ⊢ (𝜑 → Fun ◡(𝑥 ∈ 𝐴 ↦ 𝐵))

Syntax hints:   → wi 4   ∨ wo 382   ∧ wa 383   ∧ w3a 1031   = wceq 1475  Ⅎwnf 1699  [wsb 1867   ∈ wcel 1977  Ⅎwnfc 2738   ≠ wne 2780  ∀wral 2896  [wsbc 3402  ⦋csb 3499   ∖ cdif 3537   ∩ cin 3539  ∅c0 3874  {csn 4125  Disj wdisj 4553   ↦ cmpt 4643  ^◡ccnv 5037  Fun wfun 5798

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pr 4833

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-fal 1481  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-ral 2901  df-rex 2902  df-rmo 2904  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-disj 4554  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-iota 5768  df-fun 5806  df-fn 5807  df-fv 5812

This theorem is referenced by:  esumrnmpt  29441  measvunilem  29602