An array section is a portion of an array that is an array itself.
  It is an array subobject.  A section subscript list (appended to
  the array or array component) determines which portion is being
  referred to.  A reference to an array section takes the following
  form:

     array [(sect-s-list)] [(substring-range)]

     array            Is the name of an array.

     sect-s-list      Is a list of one or more section
                      subscripts (subscripts, subscript
                      triplets, or vector subscripts)
                      indicating a set of elements along
                      a particular dimension.

                      At least one of the items in the section
                      subscript list must be a subscript
                      triplet or vector subscript. Each
                      subscript and subscript triplet must be
                      a scalar numeric expression. Each vector
                      subscript must be a rank-one integer
                      expression.

     substring-range  Is a substring range in the form
                      [expr]:[expr].  Each expression specified
                      must be a scalar numeric expression.

                      The array (or array component) preceding
                      the substring range must be of type character.

  If no section subscript list is specified, the rank and shape of
  the array section is the same as the parent array.

  Otherwise, the rank of the array section is the number of vector
  subscripts and subscript triplets that appear in the list.  Its
  shape is a rank-one array where each element is the number of
  integer values in the sequence indicated by the corresponding
  subscript triplet or vector subscript.

  If any of these sequences is empty, the array section has a size of
  zero.  The subscript order of the elements of an array section is
  that of the array object that the array section represents.

  Each array section inherits the type, kind type parameter, and
  certain attributes (INTENT, PARAMETER, and TARGET) of the parent
  array.  An array section cannot inherit the POINTER attribute.

  The following shows valid references to array sections:

    REAL, DIMENSION(20) :: B
    ...
    PRINT *, B(2:20:5)  ! the section consists of elements
                        !     B(2), B(7), B(12), and B(17)
    K = (/3, 1, 4/)

    B(K) = 0.0  ! section B(K) is a rank-one array with
                ! shape (3) and size 3. (0.0 is assigned to
                ! B(1), B(3), and B(4).)

  Consider the following declaration:

    CHARACTER(LEN=15) C(10,10)

  An array section referenced as C(:,:)(1:3) is an array of shape
  (10,10) whose elements are substrings of length 3 of the
  corresponding elements of C.