Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site umcp-cs.UUCP Path: utzoo!linus!philabs!seismo!rlgvax!cvl!umcp-cs!james From: james@umcp-cs.UUCP Newsgroups: net.math Subject: fundamental group Message-ID: <3536@umcp-cs.UUCP> Date: Wed, 2-Nov-83 17:59:06 EST Article-I.D.: umcp-cs.3536 Posted: Wed Nov 2 17:59:06 1983 Date-Received: Sun, 6-Nov-83 07:53:44 EST Organization: Univ. of Maryland, Computer Science Dept. Lines: 17 Try this: What topological space has the fundamental group {e , 1} ? By {e , 1}, I mean the (only) two-element group, otherwise known as the integers mod 2, under addition. Fundamental Group: The fundamental group of a pathwise-connected topological space is the group of equivalence classes of loops in the space. A loop is a continuous map of the interval [0,1] into the space (where 0 and 1 are mapped to the same point, to close the loop). Two loops are equivalent iff they can be continuously deformed into each other (they are homotopic.) The group operation is by composition of loops (i.e. you map [0,.5] onto the first loop, and [.5,1] onto the second loop. --Jim O'Toole