Function Pointers

["Barry L. Dorough" <bdorough@phaseiv.com>]

Is there any way to implement function pointers in Ada?  Below is a
sample C program using function pointers.  How can I do this in Ada?

                                                                Thanks
in advance,
                                                                Barry
Dorough


#include <iostream.h>
double Add( double x, double y );
double Subtract( double x, double y );
double Combine( double p, double q, double (*fcn)(double r, double s) );

int main()
{
    double w = 20.0;
    double x = 5.0;
    double y = Combine( w, x, Add );
    double z = Combine( w, x, Subtract );
    cout << w << "  " << x << "  " << y << "  " << z << endl;
    return 0;
}
double Add( double x, double y )
{
    return x+y;
}
double Subtract( double x, double y )
{
    return x-y;
}
double Combine( double p, double q, double (*fcn)(double r, double s) )
{
    double a = 10.0 + p;
    return fcn( a, q );
}