Peter, that's not correct, either. A function (by definition) does not leave out any values in its domain (or it is not well-defined). If a function maps every point of its domain one-to-one into the codomain, it is injective. If a function maps every point of its domain onto the codomain (i.e. assuming every point in the codomain) , it is surjective. If a function is both injective and surjective, it is bijective. Only a bijective function has an inverse function defined on its codomain. Reinhard G. Handwerker, Sr. i18n Engineer Internet Security Systems, Inc < http://www.iss.net/> +1 404 236 2600 6303 Barfield Rd, Atlanta, GA 30328, U.S.A. Go i18n@ISS! The Power To Protect -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, February 26, 2001 10:19 To: Unicode List Subject: Re: bijective (was re: An Absurdly Brief Introduction to Unicode (was On 02/24/2001 04:43:41 PM Richard Cook wrote: >Whence does this terminology derive? Set or Mapping theory? I learned it in high school algebra. >Anyone >recommend a definitive text? I have handy the book from a topology course I took that gives definitions: Munkres, James A. 1975. Topology: A first course. Prentice-Hall. >I imagine there are more such terms ... Of terms, there is no end. >e.g., what is it called if there are elements left over in the domain >(but not in the codomain)? "Ejective"? I'm feeling "Dejective" for not >knowing these terms already ... But at least you recognised something that was likely to have been given a name: surjective. - Peter --------------------------------------------------------------------------- Peter Constable Non-Roman Script Initiative, SIL International 7500 W. Camp Wisdom Rd., Dallas, TX 75236, USA Tel: +1 972 708 7485 E-mail: <[EMAIL PROTECTED]>
RE: bijective (was re: An Absurdly Brief Introduction to Unicode
Handwerker, Reinhard (ISS Atlanta) Mon, 26 Feb 2001 09:20:12 -0800
- Re: bijective (was re: An Absurdly Brie... Handwerker, Reinhard (ISS Atlanta)