Metamath Proof Explorer


Definition df-imdir

Description: Definition of the functionalized direct image, which maps a binary relation between two given sets to its associated direct image relation. (Contributed by BJ, 16-Dec-2023)

Ref Expression
Assertion df-imdir 𝒫* = ( 𝑎 ∈ V , 𝑏 ∈ V ↦ ( 𝑟 ∈ 𝒫 ( 𝑎 × 𝑏 ) ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cimdir 𝒫*
1 va 𝑎
2 cvv V
3 vb 𝑏
4 vr 𝑟
5 1 cv 𝑎
6 3 cv 𝑏
7 5 6 cxp ( 𝑎 × 𝑏 )
8 7 cpw 𝒫 ( 𝑎 × 𝑏 )
9 vx 𝑥
10 vy 𝑦
11 9 cv 𝑥
12 11 5 wss 𝑥𝑎
13 10 cv 𝑦
14 13 6 wss 𝑦𝑏
15 12 14 wa ( 𝑥𝑎𝑦𝑏 )
16 4 cv 𝑟
17 16 11 cima ( 𝑟𝑥 )
18 17 13 wceq ( 𝑟𝑥 ) = 𝑦
19 15 18 wa ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 )
20 19 9 10 copab { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) }
21 4 8 20 cmpt ( 𝑟 ∈ 𝒫 ( 𝑎 × 𝑏 ) ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } )
22 1 3 2 2 21 cmpo ( 𝑎 ∈ V , 𝑏 ∈ V ↦ ( 𝑟 ∈ 𝒫 ( 𝑎 × 𝑏 ) ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } ) )
23 0 22 wceq 𝒫* = ( 𝑎 ∈ V , 𝑏 ∈ V ↦ ( 𝑟 ∈ 𝒫 ( 𝑎 × 𝑏 ) ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝑎𝑦𝑏 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } ) )