An assumed-shape array is a dummy argument array that assumes the
  shape of its associated actual argument array.  An assumed-shape
  specification takes the following form:

     [lower-bound]: [,[lower-bound]:] ...

  The lower bound is a specification expression.  If the lower bound
  is not specified, it is assumed to be 1.

  The rank of the array is the number of colons (:) specified.

  The value of the upper bound is the extent of the corresponding
  dimension of the associated actual argument array + lower-bound -
  1.

  The following is an example of an assumed-shape specification:

    INTERFACE
      SUBROUTINE SUB(M)
        INTEGER M(:, 1:, 5:)
      END SUBROUTINE
    END INTERFACE
    INTEGER L(20, 5:25, 10)
    CALL SUB(L)

    SUBROUTINE SUB(M)
      INTEGER M(:, 1:, 5:)
    END SUBROUTINE

  Array M has the same extents as array L, but array M has bounds
  (1:20, 1:21, 5:14).

  Note that an explicit interface is required when calling a routine
  that expects an assumed-shape or pointer array.