Steg Belsky <[log in to unmask]> wrote: > > On Wed, 8 Nov 2000 06:00:28 -0500 Carlos Thompson > <[log in to unmask]> writes: > > > -Stephen (Steg) > > > "P i Q? P oi Q? P au Q?" > > > > Is this propositional algebra in Rokbeigalmki? (did I spell it > > right?) > > Yup, you spelled it right! > I'm not sure what propositional algebra is, but this is elementary logic: It's usually known in English as propositional calculus, although that has the disadvantage of potential confusion with differential and integral calculus, which is what people mean when they say "calculus" with no modifier. It's also called 0-order logic, as opposed to first order logic, a.k.a. prepositional calculus. First order logic allows quantification over objects, and second order logic allows quantification over sets of objects. From: taliesin the storyteller <[log in to unmask]> : * Steg Belsky <[log in to unmask]> [001109 02:36]: : > (no symbol i know of) = au = "either-or" (in logic this is the negation : > of "if-and-only-if", the biconditional) : : Exclusive-or, XOR: With the other "or" known as inclusive or. : an underlined \/, or in Boolean algebra, a plus in a circle. I think it's the prevalence of the term "Boolean" in programming languages which is responsible for the identification of Boolean algebra with the propositional calculus. This has grated on me somewhat in recent years. It's true that propositional calculus is a form of Boolean algebra, but so are many other things. I don't believe the plus in a circle is used in general studies of Boolean algebras (although I could be wrong). The different forms of Boolean algebra, in fact, have several different notations, such as: General + * - 0 1 Logic v & ~ F T Set Theory U (upside down U) ' 0 (universal set) C bit maps | & ~ 0x0000 0xFFFF The equivalent of exclusive or is known as symmetric difference in set theory. BTW: Boolean algebra is named after the English mathematician George Boole (1815-1864). =========================================================================== Dennis Paul Himes <> [log in to unmask] homepage: http://www.connix.com/~dennis/dennis.htm Gladilatian page: http://www.connix.com/~dennis/glad/lang.htm Disclaimer: "True, I talk of dreams; which are the children of an idle brain, begot of nothing but vain fantasy; which is as thin of substance as the air." - Romeo & Juliet, Act I Scene iv Verse 96-99