Metamath Proof Explorer


Theorem bj-imdirval2

Description: Value of the functionalized direct image. (Contributed by BJ, 16-Dec-2023)

Ref Expression
Hypotheses bj-imdirval2.exa ( 𝜑𝐴𝑈 )
bj-imdirval2.exb ( 𝜑𝐵𝑉 )
bj-imdirval2.arg ( 𝜑𝑅 ⊆ ( 𝐴 × 𝐵 ) )
Assertion bj-imdirval2 ( 𝜑 → ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } )

Proof

Step Hyp Ref Expression
1 bj-imdirval2.exa ( 𝜑𝐴𝑈 )
2 bj-imdirval2.exb ( 𝜑𝐵𝑉 )
3 bj-imdirval2.arg ( 𝜑𝑅 ⊆ ( 𝐴 × 𝐵 ) )
4 1 2 bj-imdirval ( 𝜑 → ( 𝐴 𝒫* 𝐵 ) = ( 𝑟 ∈ 𝒫 ( 𝐴 × 𝐵 ) ↦ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } ) )
5 simpr ( ( 𝜑𝑟 = 𝑅 ) → 𝑟 = 𝑅 )
6 5 imaeq1d ( ( 𝜑𝑟 = 𝑅 ) → ( 𝑟𝑥 ) = ( 𝑅𝑥 ) )
7 6 eqeq1d ( ( 𝜑𝑟 = 𝑅 ) → ( ( 𝑟𝑥 ) = 𝑦 ↔ ( 𝑅𝑥 ) = 𝑦 ) )
8 7 anbi2d ( ( 𝜑𝑟 = 𝑅 ) → ( ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) ↔ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) ) )
9 8 opabbidv ( ( 𝜑𝑟 = 𝑅 ) → { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑟𝑥 ) = 𝑦 ) } = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } )
10 1 2 xpexd ( 𝜑 → ( 𝐴 × 𝐵 ) ∈ V )
11 10 3 sselpwd ( 𝜑𝑅 ∈ 𝒫 ( 𝐴 × 𝐵 ) )
12 1 2 bj-imdirval2lem ( 𝜑 → { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } ∈ V )
13 4 9 11 12 fvmptd ( 𝜑 → ( ( 𝐴 𝒫* 𝐵 ) ‘ 𝑅 ) = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ ( 𝑅𝑥 ) = 𝑦 ) } )