As we shall see, the courts applied English law as a whole, which forced English law to be openly maintained in the second half of the twentieth century. They are beginning to conclude that agreements between commercial parties who clearly wished to be bound and who were willing to bear the costs of enforcing their agreement are too uncertain to be enforceable. The cases show that it is much better to take the time to describe things in writing at the beginning, otherwise the law can fill in the gaps with potentially undesirable results for either party. This is a lesson to be repeated. (a) A agrees to sell B “one hundred tonnes of oil”. There is nothing that can show what kind of oil was planned. The agreement is null and void for reasons of uncertainty. In Lani Mia vs Muhammad Easin Mia , it should be considered that a lease renewal agreement that did not set the duration or rent is valid for the same period and rent as the original lease and is not cancelled out of uncertainty. The origins of this principle lie in the reluctance of English law to maintain “agreements to agree”.
The may decision and Butcher v The King  2 KB 17 provide a good illustration of this. The parties had agreed to sell rental prices at agreed prices and deliver them at agreed prices. The court found that, perhaps not surprisingly, the parties had not sealed their agreement with a legally binding contract. The Tribunal had committed to applying Rix LJ`s criteria, but ultimately came to the wrong conclusion. The High Court found that, for reasons of uncertainty, an option agreement for the purchase of oil tankers was out of the question when it provided that the date of delivery of the vessels in the exercise of the relevant options was “mutually agreed”: Teekay Tankers Ltd v STX  EWHC 253 (Comm). “In a trade agreement, the courts are all the more willing to indicate any reasonable period of time to achieve their intentions, the more the parties have advanced in their contract. If much has been done, the courts will do their best not to destroy the agreement. If nothing has been done, it is easier to say that there is no agreement between the parties because the essential conditions have not been agreed. But if an agreement has been implemented and the parties have been imposed, as is the case here, at a high cost of implementation, we should impose all reasonable conditions in order to avoid uncertainty.
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