A set is a collection of data items of  the  same  ordinal  type
  (called  the  base type).  The SET type definition specifies the
  values that can be elements of a variable of that type.

  Syntax:

     [[PACKED]] SET OF [[attribute-list]] base-type

  The 'attribute-list' is one or more  optional  identifiers  that
  provide additional information about the base type.

  The  'base-type'  is  the  ordinal  type  identifier   or   type
  definition,  or  discriminated  schema  type, from which the set
  elements  are  selected.   Note  that  real  numbers  cannot  be
  elements of a set type.

  Example:  SET OF CHAR

  Some possible set constructors for this set type are:
     ['A, 'E', 'I', 'O', 'U']
     ['B'..'D', 'F'..'H', 'J'..'N', 'P'..'T', 'V'..'Z']

1  –  Set constructor

  Set constructors are  lists  of  values  that  you  can  use  to
  initialize  a  set.   The  syntax  for  set  constructors  is as
  follows:

     [[data-type]] [ [[{component-value},...]] ]

  The 'data-type' is the  data  type  of  the  constructor.   This
  identifier  is  optional  when  used in the CONST and executable
  sections; do not  use  this  identifier  in  the  TYPE  and  VAR
  sections or in nested constructors.

  The 'component-value' specifies values within the range  of  the
  defined  data  type.   Component values can be subranges (..) to
  indicate consecutive values that appear in the  set  definition.
  These values are compile-time values; if you use the constructor
  in the executable section, you can also use run-time values.

  A set having no elements is called an empty set and  is  written
  as empty brackets ([]).

  A possible constructor for a variable of type SET OF 35..115  is
  the following:

     VAR
        Numbers : SET OF 35..115 VALUE [39, 67, 110..115];

     {In the executable section, run-time expressions are legal:}
     Numbers := [39, 67, x+95, 110..115]

  The set constructors contain up to nine values:  39, 67,  95  or
  x+95,  and  integers  between  110  and  115, inclusive.  If the
  expression x+95  evaluates  to  an  integer  outside  the  range
  35..115,  then  VSI  Pascal  includes  no  set  element for that
  expression.