An adjustable array is an explicit-shape array that is a dummy
  argument to a subprogram.  At least one bound of an adjustable
  array must be a nonconstant specification expression.  The bounds
  are determined when the subprogram is called.

  The array specification can contain integer variables that are
  either dummy arguments or variables in a common block.

  When the subprogram is entered, each dummy argument specified in
  the bounds must be associated with an actual argument.  If the
  specification includes a variable in a common block, it must have a
  defined value.  The array specification is evaluated using the
  values of the actual arguments, as well as any constants or common
  block variables that appear in the specification.

  The size of the adjustable array must be less than or equal to the
  size of the array that is its corresponding actual argument.

  To avoid possible errors in subscript evaluation, make sure that
  the bounds expressions used to declare multidimensional adjustable
  arrays match the bounds as declared by the caller.

  In the following example, the function computes the sum of the
  elements of a rank-two array.  Notice how the dummy arguments M and
  N control the iteration:

      FUNCTION MY_SUM(A, M, N)
        DIMENSION A(M, N)
        SUMX = 0.0
        DO J = 1, N
          DO I = 1, M
            SUMX = SUMX + A(I, J)
          END DO
        END DO
        MY_SUM = SUMX
      END FUNCTION

  The following are examples of calls on SUM:

    DIMENSION A1(10,35), A2(3,56)
    SUM1 = MY_SUM(A1,10,35)
    SUM2 = MY_SUM(A2,3,56)