1 double
f(double x)2 f(double x)
3 {
4   return x*x;
5 }
6 
7 double
Int(double (* f)(double),double a)8 Int(double (*f)(double), double a)
9 {
10   return (*f)(a);
11 }
12 
main()13 main()
14 {
15   if (Int(&f,2.0) != 4.0)
16     abort();
17   exit (0);
18 }
19