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