Description: The transitive closure function. (Contributed by Mario Carneiro, 23-Jun-2013)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-tc | ⊢ TC = ( 𝑥 ∈ V ↦ ∩ { 𝑦 ∣ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | ctc | ⊢ TC | |
| 1 | vx | ⊢ 𝑥 | |
| 2 | cvv | ⊢ V | |
| 3 | vy | ⊢ 𝑦 | |
| 4 | 1 | cv | ⊢ 𝑥 | 
| 5 | 3 | cv | ⊢ 𝑦 | 
| 6 | 4 5 | wss | ⊢ 𝑥 ⊆ 𝑦 | 
| 7 | 5 | wtr | ⊢ Tr 𝑦 | 
| 8 | 6 7 | wa | ⊢ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) | 
| 9 | 8 3 | cab | ⊢ { 𝑦 ∣ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) } | 
| 10 | 9 | cint | ⊢ ∩ { 𝑦 ∣ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) } | 
| 11 | 1 2 10 | cmpt | ⊢ ( 𝑥 ∈ V ↦ ∩ { 𝑦 ∣ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) } ) | 
| 12 | 0 11 | wceq | ⊢ TC = ( 𝑥 ∈ V ↦ ∩ { 𝑦 ∣ ( 𝑥 ⊆ 𝑦 ∧ Tr 𝑦 ) } ) |