Description: Operation value of the empty set. (Contributed by AV, 15-May-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | 0ov | ⊢ ( 𝐴 ∅ 𝐵 ) = ∅ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-ov | ⊢ ( 𝐴 ∅ 𝐵 ) = ( ∅ ‘ 〈 𝐴 , 𝐵 〉 ) | |
2 | 0fv | ⊢ ( ∅ ‘ 〈 𝐴 , 𝐵 〉 ) = ∅ | |
3 | 1 2 | eqtri | ⊢ ( 𝐴 ∅ 𝐵 ) = ∅ |