Metamath Proof Explorer


Theorem opwo0id

Description: An ordered pair is equal to the ordered pair without the empty set. This is because no ordered pair contains the empty set. (Contributed by AV, 15-Nov-2021)

Ref Expression
Assertion opwo0id 𝑋 , 𝑌 ⟩ = ( ⟨ 𝑋 , 𝑌 ⟩ ∖ { ∅ } )

Proof

Step Hyp Ref Expression
1 0nelop ¬ ∅ ∈ ⟨ 𝑋 , 𝑌
2 disjsn ( ( ⟨ 𝑋 , 𝑌 ⟩ ∩ { ∅ } ) = ∅ ↔ ¬ ∅ ∈ ⟨ 𝑋 , 𝑌 ⟩ )
3 1 2 mpbir ( ⟨ 𝑋 , 𝑌 ⟩ ∩ { ∅ } ) = ∅
4 disjdif2 ( ( ⟨ 𝑋 , 𝑌 ⟩ ∩ { ∅ } ) = ∅ → ( ⟨ 𝑋 , 𝑌 ⟩ ∖ { ∅ } ) = ⟨ 𝑋 , 𝑌 ⟩ )
5 3 4 ax-mp ( ⟨ 𝑋 , 𝑌 ⟩ ∖ { ∅ } ) = ⟨ 𝑋 , 𝑌
6 5 eqcomi 𝑋 , 𝑌 ⟩ = ( ⟨ 𝑋 , 𝑌 ⟩ ∖ { ∅ } )