anchor.diff:        double complex zdotu,r
         integer n,incx,incy
         double complex x(*),y(*)
  -      dotu=zdotu(n,x,incx,y,incy)
  +      r=zdotu(n,x,incx,y,incy)
         return
         end
  
positive.code:       complex cdotu,r
        integer n,incx,incy
        complex x(*),y(*)
        dotu=cdotu(n,x,incx,y,incy)
        return
        end
  c
  
negative.code:       complex cdotc,r
        integer n,incx,incy
        complex x(*),y(*)
        r=cdotc(n,x,incx,y,incy)
        return
        end
  c
  