Example of c# based rule language?

Can you provide a good example of rule definition language written in C#.
Java guys have JESS, is there anything good for C#?

What is C function example?

C Control Flow Examples. Check Prime or Armstrong Number Using User-defined Function. Check Whether a Number can be Expressed as Sum of Two Prime Numbers. String Examples in C Programming. Find Factorial of a Number Using Recursion.

This page shows some examples of open-source rules engines in C#: http://csharp-source.net/open-source/rule-engines

You can use the forward chaining inference engine that is part of Windows Workflow Foundation (.NET 3.5 and higher) The best part is that this has a free runtime licensing.

You can use the Rule Manager from Acumen Business and install the Windows Workflow Foundation adapter. Once installed, export the rules as WFRules (*.rules). A visual studio .NET solution will be generated that shows how the rule engine can be invoked standalone (no workflow is necessary)

See also http://bizknowledge.blogspot.com/search/label/Windows%20Workflow%20Foundation