Metamath Proof Explorer


Theorem brtrclfv2

Description: Two ways to indicate two elements are related by the transitive closure of a relation. (Contributed by RP, 1-Jul-2020)

Ref Expression
Assertion brtrclfv2 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → X t+ ⁡ R Y ↔ Y ∈ ⋂ f | R X ∪ f ⊆ f

Proof

Step Hyp Ref Expression
1 df-br ⊢ X ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r Y ↔ X Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r
2 1 a1i ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → X ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r Y ↔ X Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r
3 trclfv ⊢ R ∈ W → t+ ⁡ R = ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r
4 3 breqd ⊢ R ∈ W → X t+ ⁡ R Y ↔ X ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r Y
5 4 3ad2ant3 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → X t+ ⁡ R Y ↔ X ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r Y
6 elimasng ⊢ X ∈ U ∧ Y ∈ V → Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X ↔ X Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r
7 6 3adant3 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X ↔ X Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r
8 2 5 7 3bitr4d ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → X t+ ⁡ R Y ↔ Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X
9 intimasn ⊢ X ∈ U → ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X = ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X
10 9 3ad2ant1 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X = ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X
11 simpl3 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R ∈ W
12 snex ⊢ X ∈ V
13 vex ⊢ f ∈ V
14 12 13 xpex ⊢ X × f ∈ V
15 unexg ⊢ R ∈ W ∧ X × f ∈ V → R ∪ X × f ∈ V
16 11 14 15 sylancl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R ∪ X × f ∈ V
17 trclfvlb ⊢ R ∪ X × f ∈ V → R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
18 17 unssad ⊢ R ∪ X × f ∈ V → R ⊆ t+ ⁡ R ∪ X × f
19 16 18 syl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R ⊆ t+ ⁡ R ∪ X × f
20 trclfvcotrg ⊢ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
21 20 a1i ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
22 simpl1 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X ∈ U
23 snidg ⊢ X ∈ U → X ∈ X
24 22 23 syl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X ∈ X
25 inelcm ⊢ X ∈ X ∧ X ∈ X → X ∩ X ≠ ∅
26 24 24 25 syl2anc ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X ∩ X ≠ ∅
27 xpima2 ⊢ X ∩ X ≠ ∅ → X × f X = f
28 26 27 syl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X × f X = f
29 16 17 syl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
30 29 unssbd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X × f ⊆ t+ ⁡ R ∪ X × f
31 imass1 ⊢ X × f ⊆ t+ ⁡ R ∪ X × f → X × f X ⊆ t+ ⁡ R ∪ X × f X
32 30 31 syl ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X × f X ⊆ t+ ⁡ R ∪ X × f X
33 28 32 eqsstrrd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → f ⊆ t+ ⁡ R ∪ X × f X
34 imaundir ⊢ R ∪ X × f X ∪ f = R X ∪ f ∪ X × f X ∪ f
35 simpr ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R X ∪ f ⊆ f
36 imassrn ⊢ X × f X ∪ f ⊆ ran ⁡ X × f
37 rnxpss ⊢ ran ⁡ X × f ⊆ f
38 36 37 sstri ⊢ X × f X ∪ f ⊆ f
39 38 a1i ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → X × f X ∪ f ⊆ f
40 35 39 unssd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R X ∪ f ∪ X × f X ∪ f ⊆ f
41 34 40 eqsstrid ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → R ∪ X × f X ∪ f ⊆ f
42 trclimalb2 ⊢ R ∪ X × f ∈ V ∧ R ∪ X × f X ∪ f ⊆ f → t+ ⁡ R ∪ X × f X ⊆ f
43 16 41 42 syl2anc ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → t+ ⁡ R ∪ X × f X ⊆ f
44 33 43 eqssd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → f = t+ ⁡ R ∪ X × f X
45 sbcan ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X ↔ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ∧ [˙ t+ ⁡ R ∪ X × f / r]˙ f = r X
46 sbcan ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ↔ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ [˙ t+ ⁡ R ∪ X × f / r]˙ r ∘ r ⊆ r
47 fvex ⊢ t+ ⁡ R ∪ X × f ∈ V
48 sbcssg ⊢ t+ ⁡ R ∪ X × f ∈ V → [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ↔ ⦋ t+ ⁡ R ∪ X × f / r⦌ R ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
49 47 48 ax-mp ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ↔ ⦋ t+ ⁡ R ∪ X × f / r⦌ R ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
50 csbconstg ⊢ t+ ⁡ R ∪ X × f ∈ V → ⦋ t+ ⁡ R ∪ X × f / r⦌ R = R
51 47 50 ax-mp ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ R = R
52 47 csbvargi ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r = t+ ⁡ R ∪ X × f
53 51 52 sseq12i ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ R ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ↔ R ⊆ t+ ⁡ R ∪ X × f
54 49 53 bitri ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ↔ R ⊆ t+ ⁡ R ∪ X × f
55 sbcssg ⊢ t+ ⁡ R ∪ X × f ∈ V → [˙ t+ ⁡ R ∪ X × f / r]˙ r ∘ r ⊆ r ↔ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
56 47 55 ax-mp ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ r ∘ r ⊆ r ↔ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
57 csbcog ⊢ t+ ⁡ R ∪ X × f ∈ V → ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r = ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
58 47 57 ax-mp ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r = ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ ⦋ t+ ⁡ R ∪ X × f / r⦌ r
59 52 52 coeq12i ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ ⦋ t+ ⁡ R ∪ X × f / r⦌ r = t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f
60 58 59 eqtri ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r = t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f
61 60 52 sseq12i ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ∘ r ⊆ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ↔ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
62 56 61 bitri ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ r ∘ r ⊆ r ↔ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
63 54 62 anbi12i ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ [˙ t+ ⁡ R ∪ X × f / r]˙ r ∘ r ⊆ r ↔ R ⊆ t+ ⁡ R ∪ X × f ∧ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
64 46 63 bitri ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ↔ R ⊆ t+ ⁡ R ∪ X × f ∧ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f
65 sbceq2g ⊢ t+ ⁡ R ∪ X × f ∈ V → [˙ t+ ⁡ R ∪ X × f / r]˙ f = r X ↔ f = ⦋ t+ ⁡ R ∪ X × f / r⦌ r X
66 47 65 ax-mp ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ f = r X ↔ f = ⦋ t+ ⁡ R ∪ X × f / r⦌ r X
67 csbima12 ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r X = ⦋ t+ ⁡ R ∪ X × f / r⦌ r ⦋ t+ ⁡ R ∪ X × f / r⦌ X
68 52 imaeq1i ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r ⦋ t+ ⁡ R ∪ X × f / r⦌ X = t+ ⁡ R ∪ X × f ⦋ t+ ⁡ R ∪ X × f / r⦌ X
69 csbconstg ⊢ t+ ⁡ R ∪ X × f ∈ V → ⦋ t+ ⁡ R ∪ X × f / r⦌ X = X
70 47 69 ax-mp ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ X = X
71 70 imaeq2i ⊢ t+ ⁡ R ∪ X × f ⦋ t+ ⁡ R ∪ X × f / r⦌ X = t+ ⁡ R ∪ X × f X
72 67 68 71 3eqtri ⊢ ⦋ t+ ⁡ R ∪ X × f / r⦌ r X = t+ ⁡ R ∪ X × f X
73 72 eqeq2i ⊢ f = ⦋ t+ ⁡ R ∪ X × f / r⦌ r X ↔ f = t+ ⁡ R ∪ X × f X
74 66 73 bitri ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ f = r X ↔ f = t+ ⁡ R ∪ X × f X
75 64 74 anbi12i ⊢ [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ∧ [˙ t+ ⁡ R ∪ X × f / r]˙ f = r X ↔ R ⊆ t+ ⁡ R ∪ X × f ∧ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f ∧ f = t+ ⁡ R ∪ X × f X
76 45 75 sylbbr ⊢ R ⊆ t+ ⁡ R ∪ X × f ∧ t+ ⁡ R ∪ X × f ∘ t+ ⁡ R ∪ X × f ⊆ t+ ⁡ R ∪ X × f ∧ f = t+ ⁡ R ∪ X × f X → [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
77 19 21 44 76 syl21anc ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → [˙ t+ ⁡ R ∪ X × f / r]˙ R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
78 77 spesbcd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W ∧ R X ∪ f ⊆ f → ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
79 78 ex ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → R X ∪ f ⊆ f → ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
80 eqeq1 ⊢ g = f → g = s X ↔ f = s X
81 80 rexbidv ⊢ g = f → ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ↔ ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r f = s X
82 imaeq1 ⊢ s = r → s X = r X
83 82 eqeq2d ⊢ s = r → f = s X ↔ f = r X
84 83 rexab2 ⊢ ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r f = s X ↔ ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
85 81 84 bitrdi ⊢ g = f → ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ↔ ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
86 13 85 elab ⊢ f ∈ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ↔ ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ f = r X
87 79 86 imbitrrdi ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → R X ∪ f ⊆ f → f ∈ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X
88 intss1 ⊢ f ∈ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ f
89 87 88 syl6 ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → R X ∪ f ⊆ f → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ f
90 89 alrimiv ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ∀ f R X ∪ f ⊆ f → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ f
91 ssintab ⊢ ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ ⋂ f | R X ∪ f ⊆ f ↔ ∀ f R X ∪ f ⊆ f → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ f
92 90 91 sylibr ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ⊆ ⋂ f | R X ∪ f ⊆ f
93 ssintab ⊢ ⋂ f | R X ∪ f ⊆ f ⊆ ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ↔ ∀ g ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X → ⋂ f | R X ∪ f ⊆ f ⊆ g
94 82 eqeq2d ⊢ s = r → g = s X ↔ g = r X
95 94 rexab2 ⊢ ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X ↔ ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X
96 simpr ⊢ R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X → g = r X
97 imass1 ⊢ R ⊆ r → R X ⊆ r X
98 97 adantr ⊢ R ⊆ r ∧ r ∘ r ⊆ r → R X ⊆ r X
99 imass1 ⊢ R ⊆ r → R r X ⊆ r r X
100 imaco ⊢ r ∘ r X = r r X
101 imass1 ⊢ r ∘ r ⊆ r → r ∘ r X ⊆ r X
102 100 101 eqsstrrid ⊢ r ∘ r ⊆ r → r r X ⊆ r X
103 99 102 sylan9ss ⊢ R ⊆ r ∧ r ∘ r ⊆ r → R r X ⊆ r X
104 98 103 jca ⊢ R ⊆ r ∧ r ∘ r ⊆ r → R X ⊆ r X ∧ R r X ⊆ r X
105 104 adantr ⊢ R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X → R X ⊆ r X ∧ R r X ⊆ r X
106 vex ⊢ r ∈ V
107 106 imaex ⊢ r X ∈ V
108 imaundi ⊢ R X ∪ f = R X ∪ R f
109 108 sseq1i ⊢ R X ∪ f ⊆ f ↔ R X ∪ R f ⊆ f
110 unss ⊢ R X ⊆ f ∧ R f ⊆ f ↔ R X ∪ R f ⊆ f
111 109 110 bitr4i ⊢ R X ∪ f ⊆ f ↔ R X ⊆ f ∧ R f ⊆ f
112 imaeq2 ⊢ f = r X → R f = R r X
113 id ⊢ f = r X → f = r X
114 112 113 sseq12d ⊢ f = r X → R f ⊆ f ↔ R r X ⊆ r X
115 114 cleq2lem ⊢ f = r X → R X ⊆ f ∧ R f ⊆ f ↔ R X ⊆ r X ∧ R r X ⊆ r X
116 111 115 bitrid ⊢ f = r X → R X ∪ f ⊆ f ↔ R X ⊆ r X ∧ R r X ⊆ r X
117 107 116 elab ⊢ r X ∈ f | R X ∪ f ⊆ f ↔ R X ⊆ r X ∧ R r X ⊆ r X
118 105 117 sylibr ⊢ R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X → r X ∈ f | R X ∪ f ⊆ f
119 96 118 eqeltrd ⊢ R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X → g ∈ f | R X ∪ f ⊆ f
120 119 exlimiv ⊢ ∃ r R ⊆ r ∧ r ∘ r ⊆ r ∧ g = r X → g ∈ f | R X ∪ f ⊆ f
121 95 120 sylbi ⊢ ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X → g ∈ f | R X ∪ f ⊆ f
122 intss1 ⊢ g ∈ f | R X ∪ f ⊆ f → ⋂ f | R X ∪ f ⊆ f ⊆ g
123 121 122 syl ⊢ ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X → ⋂ f | R X ∪ f ⊆ f ⊆ g
124 93 123 mpgbir ⊢ ⋂ f | R X ∪ f ⊆ f ⊆ ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X
125 124 a1i ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ⋂ f | R X ∪ f ⊆ f ⊆ ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X
126 92 125 eqssd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ⋂ g | ∃ s ∈ r | R ⊆ r ∧ r ∘ r ⊆ r g = s X = ⋂ f | R X ∪ f ⊆ f
127 10 126 eqtrd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X = ⋂ f | R X ∪ f ⊆ f
128 127 eleq2d ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → Y ∈ ⋂ r | R ⊆ r ∧ r ∘ r ⊆ r X ↔ Y ∈ ⋂ f | R X ∪ f ⊆ f
129 8 128 bitrd ⊢ X ∈ U ∧ Y ∈ V ∧ R ∈ W → X t+ ⁡ R Y ↔ Y ∈ ⋂ f | R X ∪ f ⊆ f