Metamath Proof Explorer


Theorem s1cli

Description: A singleton word is a word. (Contributed by Mario Carneiro, 26-Feb-2016)

Ref Expression
Assertion s1cli ⟨“ 𝐴 ”⟩ ∈ Word V

Proof

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