ALLOCATABLE

 Specifies that an array is an allocatable array with a deferred
 shape.  The shape of an allocatable array is determined when an
 ALLOCATE statement is executed, dynamically allocating space for
 the array.

 The ALLOCATABLE attribute can be specified in a type declaration
 statement or an ALLOCATABLE statement, and takes one of the
 following forms:

 Type Declaration Statement:

  type, [att-ls,] ALLOCATABLE [,att-ls] :: a[(d-spec)] [,a[(d-spec)]]... 

 Statement:

  ALLOCATABLE [::] a[(d-spec)] [,a[(d-spec)]]... 

    type        Is a data type specifier.

    att-ls      Is an optional list of attribute specifiers.

    a           Is the name of the allocatable array; it must 
                not be a dummy argument or function result.  

    d-spec      Is a deferred-shape specification (: [,:]...). 
                Each colon represents a dimension of the array.

 If the array is given the DIMENSION attribute elsewhere in the
 program, it must be declared as a deferred-shape array.

 When the allocatable array is no longer needed, it can be
 deallocated by execution of a DEALLOCATE statement.

 During program execution, the allocation status of an allocatable
 array is one of the following:

  o  Not currently allocated

     The array was never allocated or the last operation performed
     on it was a deallocation.  Deallocation is performed:

      -  Explicitly, by using a DEALLOCATE statement.

      -  By default, when the allocatable array is a local variable
         of a procedure that does not have the SAVE attribute and is
         terminated by an END or RETURN statement.

     An array that is not currently allocated must not be referenced
     or defined.

  o  Currently allocated

     The array was allocated by an ALLOCATE statement.  Such an
     array can be referenced, defined, or deallocated.

 An allocatable array cannot be specified in a COMMON, EQUIVALENCE,
 DATA, or NAMELIST statement.

 Allocatable arrays are not saved by default.  If you want to retain
 the values of an allocatable array across procedure calls, you must
 specify the SAVE attribute for the array.

 The ALLOCATABLE attribute is compatible with the AUTOMATIC,
 DIMENSION (with deferred shape), PRIVATE, PUBLIC, SAVE, STATIC,
 TARGET, and VOLATILE attributes.

 EXAMPLES:

 The following example shows a type declaration statement specifying
 the ALLOCATABLE attribute:

    REAL, ALLOCATABLE :: Z(:, :, :)

 The following is an example of the ALLOCATABLE statement:

    REAL A, B(:)
    ALLOCATABLE :: A(:,:), B