Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles; site convex.UUCP Path: utzoo!watmath!clyde!burl!mgnetp!ihnp4!inuxc!pur-ee!uiucdcs!convex!graham From: graham@convex.UUCP Newsgroups: net.puzzle Subject: Re: Don't cross my path ! - (nf) Message-ID: <50900001@convex.UUCP> Date: Thu, 16-Aug-84 11:14:00 EDT Article-I.D.: convex.50900001 Posted: Thu Aug 16 11:14:00 1984 Date-Received: Sat, 18-Aug-84 01:47:45 EDT References: <785@abnjh.UUCP> Lines: 16 Nf-ID: #R:abnjh:-78500:convex:50900001:000:731 Nf-From: convex!graham Aug 16 10:14:00 1984 #R:abnjh:-78500:convex:50900001:000:731 convex!graham Aug 16 10:14:00 1984 There are 3 men living in 3 seperate houses within a fenced in courtyard. Following a particulary vicious argument over a gardenhose, they made up their minds never to cross each others paths again. This seemed like a good idea at the time (considering the heated debate over gun control :-) ), however, they all had to go to work at the same time of the morning. They settled on this: ... This seems to be the same as the three houses, three tanks (water, gas, oil) problem: run pipes from all tanks to all houses without crossing pipes. I believe that planar graph theory can be used to show that it is impossible, though I can't give the proof. Marv Graham; Convex Computer Corp. {allegra,ihnp4,uiucdcs,ctvax}!convex!graham