Metamath Proof Explorer


Theorem infex

Description: An infimum is a set. (Contributed by AV, 3-Sep-2020)

Ref Expression
Hypothesis infex.1 ⊢ 𝑅 Or 𝐴
Assertion infex inf ( 𝐵 , 𝐴 , 𝑅 ) ∈ V

Proof

Step Hyp Ref Expression
1 infex.1 ⊢ 𝑅 Or 𝐴
2 id ⊢ ( 𝑅 Or 𝐴 → 𝑅 Or 𝐴 )
3 2 infexd ⊢ ( 𝑅 Or 𝐴 → inf ( 𝐵 , 𝐴 , 𝑅 ) ∈ V )
4 1 3 ax-mp ⊢ inf ( 𝐵 , 𝐴 , 𝑅 ) ∈ V