! This Fortran 90 module provides a template for automatic
! differentiation.

PROGRAM TEST_AUTOMATIC_DIFFERENTIATION
   USE AUTOMATIC_DIFFERENTIATION
   IMPLICIT NONE

   TYPE(AUTODIFF) :: X, Y

   X%VALUE = 2
   X%DERIV = 1

   Y = X**2 + X

   WRITE(*,'(A,2(1X,E12.4))') 'X = ', X%VALUE
   WRITE(*,'(A,2(1X,E12.4))') 'X**2 + X = ', Y%VALUE
   WRITE(*,'(A,2(1X,E12.4))') 'DERIVATIVE OF X**2 + X = ', Y%DERIV

END PROGRAM TEST_AUTOMATIC_DIFFERENTIATION