Metamath Proof Explorer


Theorem nfmpo1

Description: Bound-variable hypothesis builder for an operation in maps-to notation. (Contributed by NM, 27-Aug-2013)

Ref Expression
Assertion nfmpo1 𝑥 ( 𝑥𝐴 , 𝑦𝐵𝐶 )

Proof

Step Hyp Ref Expression
1 df-mpo ( 𝑥𝐴 , 𝑦𝐵𝐶 ) = { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ 𝑧 = 𝐶 ) }
2 nfoprab1 𝑥 { ⟨ ⟨ 𝑥 , 𝑦 ⟩ , 𝑧 ⟩ ∣ ( ( 𝑥𝐴𝑦𝐵 ) ∧ 𝑧 = 𝐶 ) }
3 1 2 nfcxfr 𝑥 ( 𝑥𝐴 , 𝑦𝐵𝐶 )