Description: A singleton word is a word. (Contributed by Mario Carneiro, 26-Feb-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | s1cli | ⊢ 〈“ 𝐴 ”〉 ∈ Word V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ids1 | ⊢ 〈“ 𝐴 ”〉 = 〈“ ( I ‘ 𝐴 ) ”〉 | |
| 2 | fvex | ⊢ ( I ‘ 𝐴 ) ∈ V | |
| 3 | s1cl | ⊢ ( ( I ‘ 𝐴 ) ∈ V → 〈“ ( I ‘ 𝐴 ) ”〉 ∈ Word V ) | |
| 4 | 2 3 | ax-mp | ⊢ 〈“ ( I ‘ 𝐴 ) ”〉 ∈ Word V |
| 5 | 1 4 | eqeltri | ⊢ 〈“ 𝐴 ”〉 ∈ Word V |