Re: How to get rid of irrelevant Boolean variables from
- To: mathgroup at smc.vnet.net
- Subject: [mg94878] Re: [mg94828] How to get rid of irrelevant Boolean variables from
- From: Patrick Scheibe <pscheibe at trm.uni-leipzig.de>
- Date: Mon, 29 Dec 2008 06:40:41 -0500 (EST)
- References: <200812271204.HAA12519@smc.vnet.net>
Hi,
maybe Mathematica doesn't assume that x and y are booleans?
FullSimplify[(x && y) || ( ! x && y),
Assumptions -> Element[{x, y}, Booleans]]
Cheers
Patrick
On Sat, 2008-12-27 at 07:04 -0500, Vlad wrote:
> 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
>