# *** Now p is a non-empty list of [ coef, exponent ] pairs. ***

    # Convert the first term, preceded by a "-" if it's negative.
    result = (if p[0][0] < 0 then "-" else "" end) + term_to_str(*p[0])

    # Convert the rest of the terms, in each case adding the appropriate
    # + or - separating them.  
    for term in p[1...p.length]
        # Add the separator then the rep. of the term.
        result += (if term[0] < 0 then " - " else " + " end) + 
                term_to_str(*term)
    end

    ret