Metamath Proof Explorer


Definition df-ida

Description: Definition of the identity arrow, which is just the identity morphism tagged with its domain and codomain. (Contributed by FL, 26-Oct-2007) (Revised by Mario Carneiro, 11-Jan-2017)

Ref Expression
Assertion df-ida Ida = ( 𝑐 ∈ Cat ↦ ( 𝑥 ∈ ( Base ‘ 𝑐 ) ↦ ⟨ 𝑥 , 𝑥 , ( ( Id ‘ 𝑐 ) ‘ 𝑥 ) ⟩ ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cida ⊢ Ida
1 vc ⊢ 𝑐
2 ccat ⊢ Cat
3 vx ⊢ 𝑥
4 cbs ⊢ Base
5 1 cv ⊢ 𝑐
6 5 4 cfv ⊢ ( Base ‘ 𝑐 )
7 3 cv ⊢ 𝑥
8 ccid ⊢ Id
9 5 8 cfv ⊢ ( Id ‘ 𝑐 )
10 7 9 cfv ⊢ ( ( Id ‘ 𝑐 ) ‘ 𝑥 )
11 7 7 10 cotp ⊢ ⟨ 𝑥 , 𝑥 , ( ( Id ‘ 𝑐 ) ‘ 𝑥 ) ⟩
12 3 6 11 cmpt ⊢ ( 𝑥 ∈ ( Base ‘ 𝑐 ) ↦ ⟨ 𝑥 , 𝑥 , ( ( Id ‘ 𝑐 ) ‘ 𝑥 ) ⟩ )
13 1 2 12 cmpt ⊢ ( 𝑐 ∈ Cat ↦ ( 𝑥 ∈ ( Base ‘ 𝑐 ) ↦ ⟨ 𝑥 , 𝑥 , ( ( Id ‘ 𝑐 ) ‘ 𝑥 ) ⟩ ) )
14 0 13 wceq ⊢ Ida = ( 𝑐 ∈ Cat ↦ ( 𝑥 ∈ ( Base ‘ 𝑐 ) ↦ ⟨ 𝑥 , 𝑥 , ( ( Id ‘ 𝑐 ) ‘ 𝑥 ) ⟩ ) )