You are given: 

(i) The quoted ask (resp. bid) prices of a K-strike T-year call option and a K-strike T-year put option on the same stock are denoted by C^a(K, T) and P^a(K, T) (resp. C^b(K, T) and P^b(K, T)), respectively. 

(ii) The current ask and bid prices for the stock are S^a(0) and S^b(0), respectively. 

(iii) You can borrow at the rate r^b and lend at the rate r^l. 

(iv) The stock pays dividends continuously at a rate proportional to its price. The dividend yield is δ. 

Use no-arbitrage arguments to derive condition(s), in terms of the above symbols, under which you cannot profitably perform a parity arbitrage.