What was the case law from English case Gibson v Manchester City Council?

Gibson v Manchester City Council [1979] UKHL 4 is an English contract law case that dealt with the issue of unilateral contracts. In this case, the defendant, Manchester City Council, promised to pay a sum of money to anyone who found a lost dog. The plaintiff, Gibson, found the dog and claimed the reward. The court held that the defendant´s promise to pay a reward for the return of the lost dog was a unilateral contract. The court found that the defendant´s promise was an offer to enter into a contract, which the plaintiff accepted by finding and returning the dog. The court held that the contract was formed by the plaintiff´s performance of the condition specified in the defendant´s promise, which was to find and return the lost dog. The Gibson v Manchester City Council case is an important decision in English contract law and it has been widely cited in subsequent cases dealing with unilateral contracts. The case established the principle that a unilateral contract can be formed by performance, even in the absence of a formal offer and acceptance, if one party makes a clear and unconditional promise to pay a sum of money or confer a benefit in return for the performance of a specified act.