Re: How to get rid of irrelevant Boolean variables from an expression
- To: mathgroup at smc.vnet.net
- Subject: [mg94854] Re: How to get rid of irrelevant Boolean variables from an expression
- From: "Steve Luttrell" <steve at _removemefirst_luttrell.org.uk>
- Date: Mon, 29 Dec 2008 06:36:20 -0500 (EST)
- References: <gj55j3$c60$1@smc.vnet.net>
Simplify[x && y || !x && y] does what you want. -- Stephen Luttrell West Malvern, UK "Vlad" <vladtarko at gmail.com> wrote in message news:gj55j3$c60$1 at smc.vnet.net... > Hi, > > I need to simplify a Boolean expression that looks like > > x && y || !x && y > > to y alone. I.e. the expression's truth value is independent of x so it > should be left out. > > I've tried about every Mathematica function for dealing with Boolean > expressions and couldn't do this. Also, > > Equivalent[x && y || !x && y, y]//TautologyQ > > gives False. This might be because the two expressions don't have the same > number of variables (?). > > I have large truth tables so I would like to get rid of the irrelevant > Boolean variables automatically. Does anyone know how to do this? > > Thanks >