Description: The infimum regarding an empty base set is always the empty set. (Contributed by AV, 4-Sep-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | inf00 | ⊢ inf ( 𝐵 , ∅ , 𝑅 ) = ∅ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-inf | ⊢ inf ( 𝐵 , ∅ , 𝑅 ) = sup ( 𝐵 , ∅ , ◡ 𝑅 ) | |
| 2 | sup00 | ⊢ sup ( 𝐵 , ∅ , ◡ 𝑅 ) = ∅ | |
| 3 | 1 2 | eqtri | ⊢ inf ( 𝐵 , ∅ , 𝑅 ) = ∅ |