
                                %Label%

        A label is an alphanumeric string with optional subscripts.  It is
   comparable to a label found beside an equation or relation in an engi-
   neering or scientific textbook.  The subscripts of a label are surrounded
   by square brackets and seperated by commas.  Labels with no subscripts
   are implicitly defined when used for defining an expression or relation.
   Subscripted labels must be defined with a LABEL statement.

   %Example%

   þLABEL A[1..3,1..3]
   þQ : f(x) = a*x + b
   þITERATE I FROM 1 TO 3
   þITERATE J FROM 1 TO 3
   þA[I,J] : I + J

        "A" is a 3 X 3 label which has 9 components.  Q is a label for the
   equation "f(x) = a*x + b"

