// An interface that defines how things that act like mathematical functions
// of one variable behave. This interface is useful for declaring parameters
// to or variables in modules that operate on functions (e.g., integrating or
// differentiating functions, finding zeros, etc.)

// History:
//
//   January 2007 -- Created by Doug Baldwin as part of a prototype solution
//     to a CSci 240 exercise.




interface Function {
    
    
    // Functions can be evaluated at an x value, producing the corresponding
    // function value.
    
    public double value( double x );
}