Theorem isdir 18655

Description: A condition for a relation to be a direction. (Contributed by Jeff Hankins, 25-Nov-2009.) (Revised by Mario Carneiro, 22-Nov-2013.)

Hypothesis

Ref	Expression
isdir.1	⊢ 𝐴 = ∪ ∪ 𝑅

Assertion

Ref	Expression
isdir	⊢ (𝑅 ∈ 𝑉 → (𝑅 ∈ DirRel ↔ ((Rel 𝑅 ∧ ( I ↾ 𝐴) ⊆ 𝑅) ∧ ((𝑅 ∘ 𝑅) ⊆ 𝑅 ∧ (𝐴 × 𝐴) ⊆ (◡𝑅 ∘ 𝑅)))))

Proof of Theorem isdir

Dummy variable 𝑟 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		releq 5788	. . . 4 ⊢ (𝑟 = 𝑅 → (Rel 𝑟 ↔ Rel 𝑅))
2		unieq 4922	. . . . . . . 8 ⊢ (𝑟 = 𝑅 → ∪ 𝑟 = ∪ 𝑅)
3	2	unieqd 4924	. . . . . . 7 ⊢ (𝑟 = 𝑅 → ∪ ∪ 𝑟 = ∪ ∪ 𝑅)
4		isdir.1	. . . . . . 7 ⊢ 𝐴 = ∪ ∪ 𝑅
5	3, 4	eqtr4di 2792	. . . . . 6 ⊢ (𝑟 = 𝑅 → ∪ ∪ 𝑟 = 𝐴)
6	5	reseq2d 5999	. . . . 5 ⊢ (𝑟 = 𝑅 → ( I ↾ ∪ ∪ 𝑟) = ( I ↾ 𝐴))
7		id 22	. . . . 5 ⊢ (𝑟 = 𝑅 → 𝑟 = 𝑅)
8	6, 7	sseq12d 4028	. . . 4 ⊢ (𝑟 = 𝑅 → (( I ↾ ∪ ∪ 𝑟) ⊆ 𝑟 ↔ ( I ↾ 𝐴) ⊆ 𝑅))
9	1, 8	anbi12d 632	. . 3 ⊢ (𝑟 = 𝑅 → ((Rel 𝑟 ∧ ( I ↾ ∪ ∪ 𝑟) ⊆ 𝑟) ↔ (Rel 𝑅 ∧ ( I ↾ 𝐴) ⊆ 𝑅)))
10	7, 7	coeq12d 5877	. . . . 5 ⊢ (𝑟 = 𝑅 → (𝑟 ∘ 𝑟) = (𝑅 ∘ 𝑅))
11	10, 7	sseq12d 4028	. . . 4 ⊢ (𝑟 = 𝑅 → ((𝑟 ∘ 𝑟) ⊆ 𝑟 ↔ (𝑅 ∘ 𝑅) ⊆ 𝑅))
12	5	sqxpeqd 5720	. . . . 5 ⊢ (𝑟 = 𝑅 → (∪ ∪ 𝑟 × ∪ ∪ 𝑟) = (𝐴 × 𝐴))
13		cnveq 5886	. . . . . 6 ⊢ (𝑟 = 𝑅 → ◡𝑟 = ◡𝑅)
14	13, 7	coeq12d 5877	. . . . 5 ⊢ (𝑟 = 𝑅 → (◡𝑟 ∘ 𝑟) = (◡𝑅 ∘ 𝑅))
15	12, 14	sseq12d 4028	. . . 4 ⊢ (𝑟 = 𝑅 → ((∪ ∪ 𝑟 × ∪ ∪ 𝑟) ⊆ (◡𝑟 ∘ 𝑟) ↔ (𝐴 × 𝐴) ⊆ (◡𝑅 ∘ 𝑅)))
16	11, 15	anbi12d 632	. . 3 ⊢ (𝑟 = 𝑅 → (((𝑟 ∘ 𝑟) ⊆ 𝑟 ∧ (∪ ∪ 𝑟 × ∪ ∪ 𝑟) ⊆ (◡𝑟 ∘ 𝑟)) ↔ ((𝑅 ∘ 𝑅) ⊆ 𝑅 ∧ (𝐴 × 𝐴) ⊆ (◡𝑅 ∘ 𝑅))))
17	9, 16	anbi12d 632	. 2 ⊢ (𝑟 = 𝑅 → (((Rel 𝑟 ∧ ( I ↾ ∪ ∪ 𝑟) ⊆ 𝑟) ∧ ((𝑟 ∘ 𝑟) ⊆ 𝑟 ∧ (∪ ∪ 𝑟 × ∪ ∪ 𝑟) ⊆ (◡𝑟 ∘ 𝑟))) ↔ ((Rel 𝑅 ∧ ( I ↾ 𝐴) ⊆ 𝑅) ∧ ((𝑅 ∘ 𝑅) ⊆ 𝑅 ∧ (𝐴 × 𝐴) ⊆ (◡𝑅 ∘ 𝑅)))))
18		df-dir 18653	. 2 ⊢ DirRel = {𝑟 ∣ ((Rel 𝑟 ∧ ( I ↾ ∪ ∪ 𝑟) ⊆ 𝑟) ∧ ((𝑟 ∘ 𝑟) ⊆ 𝑟 ∧ (∪ ∪ 𝑟 × ∪ ∪ 𝑟) ⊆ (◡𝑟 ∘ 𝑟)))}
19	17, 18	elab2g 3682	1 ⊢ (𝑅 ∈ 𝑉 → (𝑅 ∈ DirRel ↔ ((Rel 𝑅 ∧ ( I ↾ 𝐴) ⊆ 𝑅) ∧ ((𝑅 ∘ 𝑅) ⊆ 𝑅 ∧ (𝐴 × 𝐴) ⊆ (◡𝑅 ∘ 𝑅)))))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1536   ∈ wcel 2105   ⊆ wss 3962  ∪ cuni 4911   I cid 5581   × cxp 5686  ^◡ccnv 5687   ↾ cres 5690   ∘ ccom 5692  Rel wrel 5693  DirRelcdir 18651

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1791  ax-4 1805  ax-5 1907  ax-6 1964  ax-7 2004  ax-8 2107  ax-9 2115  ax-ext 2705

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1539  df-ex 1776  df-sb 2062  df-clab 2712  df-cleq 2726  df-clel 2813  df-rab 3433  df-v 3479  df-in 3969  df-ss 3979  df-uni 4912  df-br 5148  df-opab 5210  df-xp 5694  df-rel 5695  df-cnv 5696  df-co 5697  df-res 5700  df-dir 18653

This theorem is referenced by:  reldir  18656  dirdm  18657  dirref  18658  dirtr  18659  dirge  18660  tsrdir  18661  filnetlem3  36362