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sci / sci.math.symbolic / Re: why this difference in simplification behavior between Mathematicaand Maple

SubjectAuthor
* why this difference in simplification behavior between Mathematica and MapleNasser M. Abbasi
`* Re: why this difference in simplification behavior between Mathematicaand Mapleclicliclic@freenet.de
 `- Re: why this difference in simplification behavior between Mathematicaand MapleNasser M. Abbasi

1
Subject: why this difference in simplification behavior between Mathematica and Maple
From: Nasser M. Abbasi
Newsgroups: sci.math.symbolic
Organization: A noiseless patient Spider
Date: Wed, 11 Oct 2023 04:15 UTC
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From: nma@12000.org (Nasser M. Abbasi)
Newsgroups: sci.math.symbolic
Subject: why this difference in simplification behavior between Mathematica
and Maple
Date: Tue, 10 Oct 2023 23:15:43 -0500
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in Mathematica

eq= a==a-x
Simplify[eq]

gives what is expected, which is

x==0

in Maple

eq:=a=a-x;
simplify(eq)

returns back a=a-x. So it did not do anything.

Why Maple does not do such simplification automatically as
Mathematica? Using option "size" does not help

eq:=a=a-x;
simplify(eq,size)

Only way I found in Maple is to manually convert
the equation to put everything on one side, like this

eq:=a=a-x;
simplify( lhs(eq)-rhs(eq) = 0 );

x=0

What is the logic that makes Maple not simplify a=a-x
to x=0 automatically? I do not see it myself.

Does your CAS simplify this automatically also?

--Nasser

Subject: Re: why this difference in simplification behavior between Mathematicaand Maple
From: clicliclic@freenet.d
Newsgroups: sci.math.symbolic
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Date: Wed, 11 Oct 2023 15:26 UTC
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From: nobody@nowhere.invalid (clicliclic@freenet.de)
Newsgroups: sci.math.symbolic
Subject: Re: why this difference in simplification behavior between
Mathematicaand Maple
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"Nasser M. Abbasi" schrieb:
>
> in Mathematica
>
> eq= a==a-x
> Simplify[eq]
>
> gives what is expected, which is
>
> x==0
>
> in Maple
>
> eq:=a=a-x;
> simplify(eq)
>
> returns back a=a-x. So it did not do anything.
>
> Why Maple does not do such simplification automatically as
> Mathematica? Using option "size" does not help
>
> eq:=a=a-x;
> simplify(eq,size)
>
> Only way I found in Maple is to manually convert
> the equation to put everything on one side, like this
>
> eq:=a=a-x;
> simplify( lhs(eq)-rhs(eq) = 0 );
>
> x=0
>
> What is the logic that makes Maple not simplify a=a-x
> to x=0 automatically? I do not see it myself.
>
> Does your CAS simplify this automatically also?
>

There is no explicit simplification command in Derive 6.10, only a
simplification button, and clicking this button doesn't change your
equation:

a = a - x
a = a - x

For an explicit simplification command one may define a dummy
procedure, however, which then indeed simplifies you equation:

eval(t) := t

eval(a = a - x)
x = 0

the FACTOR and EXAND commands in Derive also work here:

FACTOR(a = a - x)
x = 0

EXPAND(a = a - x)
x = 0

Perhaps Maple operates in a similar way.

Martin.

Subject: Re: why this difference in simplification behavior between Mathematicaand Maple
From: Nasser M. Abbasi
Newsgroups: sci.math.symbolic
Organization: A noiseless patient Spider
Date: Wed, 11 Oct 2023 18:21 UTC
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From: nma@12000.org (Nasser M. Abbasi)
Newsgroups: sci.math.symbolic
Subject: Re: why this difference in simplification behavior between
Mathematicaand Maple
Date: Wed, 11 Oct 2023 13:21:24 -0500
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On 10/11/2023 10:26 AM, clicliclic@freenet.de wrote:

> Perhaps Maple operates in a similar way.
>
> Martin.

May be. I've been using Maple for long time, and I just
noticed this only now, when I was looking at some
result and noticed

ln(x) = ln(x) + .... etc...

Even thought I did simplify on the equation before.

So I had to change all my code which simplifies
equations, by first rewriting the equation as
lhs(eq)-rhs(eq)=0 and only then call simplify.

I think Mathematica's way is more natural. But may be
there is a good reason why Maple does not simplify it,
and that is why I asked.

btw, sympy also does it like Mathematica:

--------------------------------
>python
Python 3.11.3 (main, Apr 5 2023, 15:52:25) [GCC 12.2.1 20230201] on linux
>>> from sympy import *
>>> a,x = symbols('a x')
>>> eq=Eq(a,a-x)
>>> eq
Eq(a, a - x)

>>> simplify(eq)
Eq(x, 0)

-------------------

--Nasser

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