AK.Symbol.IsSymbolListImmutableConstant C# (CSharp) Method

        private bool IsSymbolListImmutableConstant(SymbolList l)
        {
            var len = l.Length;
            for (int k = 0; k < len; k++)
            {
                var s = l.getSymbol(k);
                if (s.type == SymbolType.RealValue)
                {
                    if (s.variable != null)
                    {
                        return false;
                    }
                }
                else if (s.type == SymbolType.FuncCustom && !s.customFunc.enableSymbolicationTimeEvaluation)
                {
                    return false;
                }
                else if (s.type == SymbolType.StringVariable)
                {
                    return false;
                }
                else if (s.type == SymbolType.SubExpression)
                {
                    if (!IsSymbolListImmutableConstant(s.subExpression))
                    {
                        return false;
                    }
                }
            }
            return true;
        }