Arithmetica.MathExpressionContext.Resolve C# (CSharp) Method

        public MathExpression Resolve(string variable)
        {
            MathExpression expression = this.ResolveSafe(variable);
            if (expression == null)
            {
                string message = string.Format("The variable '{0}' has not been defined.", variable);
                throw new MathExpressionException(message);
            }
            return expression;
        }