e.split(/\s+/)
        if str =~ /^\-?\d+$/
            retval.push(str.to_i)
        else
            raise TypeError.new
        end
    end

    return retval
end

#
# Take a coeff and an exponent and return the string representation, ignoring
# the sign of the coefficient.
def term_to_str(coef, exp)
    ret = ""

    # Show coeff, unless it's 1 or at the right
    coef = coef.abs
    ret = coef.to_s     unless coef == 1 && exp > 0
    ret += "x" if exp > 0                               # x if exponent n