<Li> An example of a suspensive time clause would be one that permits a car buyer to take the purchased vehicle now, but only commence payment in three weeks . In other words, the agreement suspends the date of payment until a certain date in the future . </Li> <Li> A resolutive time clause stipulates the duration of the contract, after which it ceases . Although it comes into existence and is performed right away, it will, at a certain future point, be resolved and the obligation terminated . Lease contracts and fixed period contracts of employment are common examples . </Li> <P> Other significant contractual terms include suppositions, modal clauses, exemption clauses and non-variation clauses . </P> <P> The effect of a contract or obligation is often made contingent on the truth of an assumption the parties have made about a past or present fact . If Johann and Piet, for example, are negotiating a contract to buy and sell a painting, Johann may stipulate that he will make the purchase only if the painting is an original Rembrandt . They call in an expert . If their supposition is confirmed, the contract proceeds, if not, the contract falls away . Similarly, Fourie v CDMO Homes involved a sale of land, adjacent to a river, by CDMO to Fourie, whose offer had been subject to the following condition: that there were pump rights to the river . Although the parties were unsure that this was so, they concluded their agreement on the supposition that pump rights existed . </P>

Who decides the content of a contract and on what basis