ThmDex – An index of mathematical definitions, results, and conjectures.
Formulation F11589 on D221: Alphabet
F11589
Formulation 0
A D3504: Set of symbols $\mathcal{A}$ is an alphabet if and only if
(1) $\mathcal{A}$ is a D2115: Nonempty set
(2) $\mathcal{A}$ is a D17: Finite set