double x[2]
attr_praxis(1e-5, 1, 1)

func f() {local t1, t2, t3
        return ($1-1)^2 + 2*($2 - 2)^4
}

fit_praxis(2, "f", &x[0])

double a[2]

{
  printf( "f(%g,%g)=%g\n", x[0], x[1], f(x[0],x[1]))

  for i=0,1 {
	pval = pval_praxis(i, &a)
	printf("i=%d principal value = %g ", i, pval)
	printf("axis = (%g, %g)", a[0], a[1])
	printf("\n")
  }
}
