[Rule] public IExpr Literal([NT] LitExpr e) => e;
/// <summary> A named parameter with a default value. </summary> [Rule] public FuncAssign.Param DefaultParameter( [T(Tk.Id)] string name, [T(Tk.Assign)] Tk a, [NT] LitExpr dflt) => new FuncAssign.Param(name, dflt);