Newsgroups: rec.puzzles
From: hoey@zogwarg.etl.army.mil (Dan Hoey)
Date: 11 Jul 91 17:26:52 GMT
Subject: Re: Help on a Boolean logic problem

mo...@thunder.mcrcim.mcgill.edu (der Mouse) writes:

>e...@hpsciz.sc.hp.com (Evan Whitney) writes:

>> ... by using a recursive technique, you can invert N digital
>> signals with only 2 inverters....

>It initially looks as though you can, but you can't.  The resulting
>circuit contains feedback loops and in practice will oscillate; I
>recall reading an article by someone who actually tried building the
>thing.

Does anyone have a citation to this article, or other info on the
problem?  Has it been proven impossible for any inverter-building
scheme, or just the one someone tried?

Dan Hoey
Hoey@AIC.NRL.Navy.Mil