LWBtheory: Information about some propositional logics via the WWW

Imagine that you are not sure how the Hilbert-style calculus for S4 looks like, and somebody has taken your book about modal logics off your desk. No problem if you have an internet access: Open http://lwbwww.unive.ch:8080/LWBtheory.html, in a WWW browser, search for Hilbert-style calculus, in the chapter about S4, and after a few seconds you obtain the calculus, together with an example of a proof of a formula in this calculus. LWBtheory contains only a relatively small amount of information concerning some propositional non-classical logics and non-monotonic systems. However, even if your favourite subjects are not covered, it can be of some interest to you, since it shows the today's possibilities and can help to obtain improved, more comprehensive systems in the future.