Re: it isn't strange?!
- To: mathgroup at smc.vnet.net
- Subject: [mg116133] Re: it isn't strange?!
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Thu, 3 Feb 2011 05:29:01 -0500 (EST)
I will assume that "pb" means peanut butter.
So here is your peanut butter:
conditions =
Reduce[Max[a, b] == Max[c, d], c, Reals] /. {And -> List, Or -> List}
{{d < Max[a, b], c == Max[a, b]}, {d == Max[a, b], c <= Max[a, b]}}
conditions /. {d -> 2, a -> 4, b -> 3, c -> 6}
And @@@ %
{{True, False}, {False, False}}
{False, False}
conditions /. {d -> 4, a -> 4, b -> 3, c -> 6}
And @@@ %
{{False, False}, {True, False}}
{False, False}
A tautology is a logical statement that's true for every value of the
variables.
Your conditions are NOT a tautology, as your two examples prove.
Bobby
On Wed, 02 Feb 2011 05:06:39 -0600, olfa <olfa.mraihi at yahoo.fr> wrote:
> Hi Mathematica community,
>
> here is my pb:
>
> input:
> Reduce[Max[a, b] == Max[c, d], c, Reals]
> output:
> (d < Max[a, b] && c == Max[a, b]) || (d == Max[a, b] && c <= Max[a,
> b])
>
> when testing this output with 2 initialisations:
> d = 2 a = 4 b = 3 c = 6 here d < Max[4, 3] but c is not equal to
> Max[4, 3]
>
> d = 4 a = 4 b = 3 c = 6 here d = Max[4, 3] but c is not <= to
> Max[4, 3]
>
> where is the pb?!
>
--
DrMajorBob at yahoo.com