Metamath Proof Explorer


Definition df-topon

Description: Define the function that associates with a set the set of topologies on it. (Contributed by Stefan O'Rear, 31-Jan-2015)

Ref Expression
Assertion df-topon TopOn = ( 𝑏 ∈ V ↦ { 𝑗 ∈ Top ∣ 𝑏 = 𝑗 } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 ctopon TopOn
1 vb 𝑏
2 cvv V
3 vj 𝑗
4 ctop Top
5 1 cv 𝑏
6 3 cv 𝑗
7 6 cuni 𝑗
8 5 7 wceq 𝑏 = 𝑗
9 8 3 4 crab { 𝑗 ∈ Top ∣ 𝑏 = 𝑗 }
10 1 2 9 cmpt ( 𝑏 ∈ V ↦ { 𝑗 ∈ Top ∣ 𝑏 = 𝑗 } )
11 0 10 wceq TopOn = ( 𝑏 ∈ V ↦ { 𝑗 ∈ Top ∣ 𝑏 = 𝑗 } )