The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In [1] the following theorem relating the existence of one-element base for spacious class of axiomatizable propositional calculus has been given: Theorem 1. System L, as well as each axiomatizable system propositional calculus, contains sentences "CpCqp" and „CpCqCCpCqrr" (or "CpCqCCpCqrCsr"), possesses the base consisting of only one sentence 1. In Postscript added to the...
In this article we consider two systems of Lukasiewicz's three- valued modal propositional calculus. One of them is the system based on such primary terms as the disjunction (A), negation (N) and necessity (L), whereas the second is based on such primary terms as the implication (C), negation (N) and definitively improved by modal necessity terms. The both systems are definitively equivalent.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.