Description: A function does not contain the empty set. (Contributed by BJ, 26-Nov-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | 0nelfun | ⊢ ( Fun 𝑅 → ∅ ∉ 𝑅 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | funrel | ⊢ ( Fun 𝑅 → Rel 𝑅 ) | |
2 | 0nelrel | ⊢ ( Rel 𝑅 → ∅ ∉ 𝑅 ) | |
3 | 1 2 | syl | ⊢ ( Fun 𝑅 → ∅ ∉ 𝑅 ) |