Metamath Proof Explorer


Definition df-metid

Description: Define the metric identification relation for a pseudometric. (Contributed by Thierry Arnoux, 7-Feb-2018)

Ref Expression
Assertion df-metid ~Met = ( 𝑑 ran PsMet ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 ) ∧ ( 𝑥 𝑑 𝑦 ) = 0 ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cmetid ~Met
1 vd 𝑑
2 cpsmet PsMet
3 2 crn ran PsMet
4 3 cuni ran PsMet
5 vx 𝑥
6 vy 𝑦
7 5 cv 𝑥
8 1 cv 𝑑
9 8 cdm dom 𝑑
10 9 cdm dom dom 𝑑
11 7 10 wcel 𝑥 ∈ dom dom 𝑑
12 6 cv 𝑦
13 12 10 wcel 𝑦 ∈ dom dom 𝑑
14 11 13 wa ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 )
15 7 12 8 co ( 𝑥 𝑑 𝑦 )
16 cc0 0
17 15 16 wceq ( 𝑥 𝑑 𝑦 ) = 0
18 14 17 wa ( ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 ) ∧ ( 𝑥 𝑑 𝑦 ) = 0 )
19 18 5 6 copab { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 ) ∧ ( 𝑥 𝑑 𝑦 ) = 0 ) }
20 1 4 19 cmpt ( 𝑑 ran PsMet ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 ) ∧ ( 𝑥 𝑑 𝑦 ) = 0 ) } )
21 0 20 wceq ~Met = ( 𝑑 ran PsMet ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥 ∈ dom dom 𝑑𝑦 ∈ dom dom 𝑑 ) ∧ ( 𝑥 𝑑 𝑦 ) = 0 ) } )