bcParser.NET is a mathematical expression parser .NET component that can be used with Visual Studio, C#, VB, VC++, Borland Delphi.NET.

bcParser.NET Component features include:

Easy to use component API.
Comes with predefined functions.
You can create custom functions/variables and get a callback to your own functions that you define in your source code.
Optimization: Constant expression elimination for repeated tasks.
Strings are supported in the expression.
Analytic Operators: +, -, /, *, ^
Logical Operators: <, >, =, &, |, !, <>, <=, >=
Paranthesis: (, {, [
Functions in the form of: f(x,y,z,...)
List of predefined functions is available in the documentation.
Royalty free distribution at affordable price.
Source code is included.