It may be added to the matter of the reliance interest that from the nature of the agreement it can be concluded that the parties did not intend that it would be permanently binding. The reason for this lies in the special nature of tax matters in general, and property tax matters in particular, which by their nature depend on legislative developments from time to time, which may change the rates of tax liability while changing definitions and classifications. Governmental agreements on matters governed by tax legislation, which changes frequently, both in relation to tariffs and with regard to asset classifications, are not supposed to survive forever, especially when an extreme and intolerable gap has been created between their content and the law, which is binding on all residents (High Court of Justice 5705/90 Fertilizers and Chemical Substances v. Kiryat Ata Municipality, paragraph 13 ([Published in Nevo], 16.5.1995)). The assumption is that the parties to the agreement were aware of the limitations stated in this situation, and against this background it is necessary to understand the essence of the contractual reliance interest that should be attributed to the related individual as a party to the governmental contract.
- And sixth, in the realm of contract law, an ordinary contract is not valid forever until a date is set for its expiration. After a reasonable time has passed, and within the framework of the duty of good faith in the performance of a contract, a party to the contract, whose expiration date has not been set, may notify the other party of its intention to be released from it in view of the passage of time. This principle applies by virtue of the law to a governmental contract as well. The expiration of time in a contract for which there is no period of applicability, is also an important circumstance that must be taken into account in the framework of all the relevant considerations regarding the release of the public authority from the constraints of the agreement:
"What, then, is the law of a contract drawn up for an indefinite period? - - -