Description: Transitive closure of a relation. This is the smallest superset which has the transitive property. (Contributed by FL, 27-Jun-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | df-trcl | ⊢ t+ = ( 𝑥 ∈ V ↦ ∩ { 𝑧 ∣ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | ctcl | ⊢ t+ | |
1 | vx | ⊢ 𝑥 | |
2 | cvv | ⊢ V | |
3 | vz | ⊢ 𝑧 | |
4 | 1 | cv | ⊢ 𝑥 |
5 | 3 | cv | ⊢ 𝑧 |
6 | 4 5 | wss | ⊢ 𝑥 ⊆ 𝑧 |
7 | 5 5 | ccom | ⊢ ( 𝑧 ∘ 𝑧 ) |
8 | 7 5 | wss | ⊢ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 |
9 | 6 8 | wa | ⊢ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) |
10 | 9 3 | cab | ⊢ { 𝑧 ∣ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) } |
11 | 10 | cint | ⊢ ∩ { 𝑧 ∣ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) } |
12 | 1 2 11 | cmpt | ⊢ ( 𝑥 ∈ V ↦ ∩ { 𝑧 ∣ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) } ) |
13 | 0 12 | wceq | ⊢ t+ = ( 𝑥 ∈ V ↦ ∩ { 𝑧 ∣ ( 𝑥 ⊆ 𝑧 ∧ ( 𝑧 ∘ 𝑧 ) ⊆ 𝑧 ) } ) |