Precision Expression Evaluator is a powerful OCX control which enables your applications to treat numeric or logical mathematical expressions. Ask to the user an expression which states the relationship between your variables, or declares logical properties and constraints: with this control you will be able to calculate the expression's result according to the user's formula or decide whether a user's constraint is verified. Give to the user full freedom: ask him a symbolic expression instead of letting him choose between predefined calculation algorithms. Of course you can check the expression's correctness and warn the user with appropriate messages.