Thank you, Brent, This is quite clear. Hopefully I can apply it as clearly to Bruno's examples. marty a.

----- Original Message ----- From: "Brent Meeker" <meeke...@dslextreme.com> To: <everything-list@googlegroups.com> Sent: Saturday, June 06, 2009 8:03 PM Subject: Re: The seven step-Mathematical preliminaries 2 > > m.a. wrote: >> *Okay, so is it true to say that things written in EXTENSION are never >> in formula style but are translated into formulas when we put them >> into INTENSION form? You can see that my difficulty with math >> arises from an inability to master even the simplest definitions. >> marty a.* > > It's not that technical. I could define the set of books on my shelf by > giving a list of titles: "The Comprehensible Cosmos", "Set Theory and > It's Philosophy", "Overshoot", "Quintessence". That would be a > definition by extension. Or I could point to them in succession and > say, "That and that and that and that." which would be a definition by > ostension. Or I could just say, "The books on my shelf." which is a > definition by intension. An intensional definition is a descriptive > phrase with an implicit variable, which in logic you might write as: The > set of things x such that x is a book and x is on my shelf. > > Brent > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---