This function returns the lower bound  for  ordinal  types,  SET
  base types, and array indexes.

  Syntax:

     LOWER( x [[, n]] )

  The parameter 'x'  is  a  type  identifier  or  variable  of  an
  ordinal,  SET,  or  ARRAY type.  The parameter 'n' is an integer
  constant that denotes a dimension of 'x', if 'x'  is  an  array.
  If  'x' is an array and if you omit the 'n', VSI Pascal uses the
  default value 1.  If 'x' is an array, LOWER  returns  the  lower
  bound  of  the nth dimension of 'x'.  If 'x' is an ordinal type,
  LOWER returns the lower bound or smallest value.  If  'x'  is  a
  SET, LOWER returns the lower bound of the SET base type.