<P> Pinnel's Case (1602) 5 Co . Rep. 117a, also known as Penny v Cole, is an important case in English contract law, on the doctrine of part performance . In it, Sir Edward Coke opined that a part payment of a debt could not extinguish the obligation to pay the whole . </P> <P> Pinnel sued Cole, in an action of debt upon a bond, for the sum of £ 8 10s . The defendant, Cole, argued he had, at Pinnel's request, tendered £ 5 2s 2d before the debt was due, and the plaintiff had accepted in full satisfaction for the debt . </P>

What is the rule in pinnel's case