STATEMENTS

  PPL recognizes statements with specified arguments to perform the
  specified operations.  Some statements require no arguments, in which
  case there is nothing following the statement.  If arguments are
  required, they may be of two types, expression and variable.

  Expression arguments may all be expressions of any type, but will be
  converted to one of the following types prior to function evaluation:

    BEXP (BOOLEAN)
    DEXP (DATE)
    IEXP (INTEGER)
    MEXP (MONEY)
    SEXP (STRING)
    TEXP (TIME)

  Variable arguments (VAR) may be variables of any type, but may be
  converted to and from an appropriate type in order to accomplish the
  required statement.