NAME
       incr - Increment the value of a variable

SYNOPSIS
       incr varName ?increment?


DESCRIPTION
       Increments  the value stored in the variable whose name is
       varName.  The value of the variable must  be  an  integer.
       If  increment is supplied then its value (which must be an
       integer) is  added  to  the  value  of  variable  varName;
       otherwise  1 is added to varName.  The new value is stored
       as a decimal string in variable varName and also  returned
       as result.


KEYWORDS
