fact: Definition dom_symboltype {σ} : SymbolType σ → list (Sort σ) := ne_list.front.
imports: HoTT.Utf8Minimal HoTT.Basics HoTT.Classes.implementations.ne_list HoTT.Classes.implementations.family_prod HoTT.Types HoTT.HSet HoTT.Classes.implementations.list