This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: The singleton of a set is not empty. (Contributed by NM, 14-Dec-2008)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | snnzg | ⊢ ( 𝐴 ∈ 𝑉 → { 𝐴 } ≠ ∅ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | snidg | ⊢ ( 𝐴 ∈ 𝑉 → 𝐴 ∈ { 𝐴 } ) | |
| 2 | 1 | ne0d | ⊢ ( 𝐴 ∈ 𝑉 → { 𝐴 } ≠ ∅ ) |