This is a question about contract law.

In the contract (between 2 parties – let’s call them A and B for clarity) under consideration, there is a clause that grants A the right to “demand” payment from B in certain circumstances. However, there is no corresponding duty explicit in the contract on B to comply with such a demand. My question is this: is there any special meaning of the word ‘demand’ in English contract law that implies into a contract a duty to comply with the demand – i.e. will B, in entering into the contract, enter into an obligation to comply with this demand, should the demand be made?