Metamath Proof Explorer


Theorem tposid

Description: Swap an ordered pair. (Contributed by Zhi Wang, 5-Oct-2025)

Ref Expression
Assertion tposid ( 𝑋 tpos I 𝑌 ) = ⟨ 𝑌 , 𝑋 ⟩

Proof

Step Hyp Ref Expression
1 ovtpos ⊢ ( 𝑋 tpos I 𝑌 ) = ( 𝑌 I 𝑋 )
2 df-ov ⊢ ( 𝑌 I 𝑋 ) = ( I ‘ ⟨ 𝑌 , 𝑋 ⟩ )
3 opex ⊢ ⟨ 𝑌 , 𝑋 ⟩ ∈ V
4 fvi ⊢ ( ⟨ 𝑌 , 𝑋 ⟩ ∈ V → ( I ‘ ⟨ 𝑌 , 𝑋 ⟩ ) = ⟨ 𝑌 , 𝑋 ⟩ )
5 3 4 ax-mp ⊢ ( I ‘ ⟨ 𝑌 , 𝑋 ⟩ ) = ⟨ 𝑌 , 𝑋 ⟩
6 1 2 5 3eqtri ⊢ ( 𝑋 tpos I 𝑌 ) = ⟨ 𝑌 , 𝑋 ⟩