Trouble with multiple assumings

[Tester]

Hi,
using Maple 16 I am having great trouble setting up
multiple simultaneouis assumptions on variables.

I want to explain Maple to assume all of the following:
a > 0
-a < b < a
-a < c < a
-a < d < a
everthing real

I have been trying all sorts of combinations of
assume(...) and
additional(...),
but nothing seems to work.

When I inspect the variables with about(...) or with things like
is( a > 0 )
is( b^2 <a^2 )
is( c^2 <a^2 )
is( d^2 <a^2 ),
I expect to get 4 times true, but to no avail.

Any idea anyone?
TIA

[Axel Vogt]

myAssumptions:= a > 0, -a < b,b < a, -a < c,c < a, -a < d,d < a;

assume (myAssumptions); # now Maple knows it

myParams:=[a,b,c,d];
map( getassumptions, myParams ); # shows, how Maple uses it

is( a > 0 );
is( b^2 <a^2 );
is( c^2 <a^2 );

is( d^2 <a^2 );
true
true
true
true

[Tester]

When I do this in document mode, I get 4 times false.
When I do this in worksheet mode with 2d math input,
I get 4 times false.
When I do this in worksheet mode with 2d maple input,
I get 4 times true!
When I convert the previous to 2D-math ot copy/paste
it into a new document mode sheet, I get 4 times true!

But then again, the same goes for a simple one-line
assume( a > 0, -a < b,b < a, -a < c,c < a, -a < d,d < a );
which is what the documentation suggests in the first
place. I had tried that dozens of times before and it never
worked.

Hey, what is going on here?
When I *type* the following
assume( a > 0, -a < b,b < a, -a < c,c < a, -a < d,d < a );

is( a > 0 ); is( b^2 <a^2 ); is( c^2 <a^2 ); > is( d^2 <a^2 );

I get 4 times true - in any mode.
When I copy/paste it, I get four times false.
???

Tester

[A N Niel]

In article <5119f390$0$3107$ba62...@news.skynet.be>, Tester

<tes...@hotmail.not> wrote:

>
> Hey, what is going on here?
> When I *type* the following
> assume( a > 0, -a < b,b < a, -a < c,c < a, -a < d,d < a );
> is( a > 0 ); is( b^2 <a^2 ); is( c^2 <a^2 ); > is( d^2 <a^2 );
> I get 4 times true - in any mode.
> When I copy/paste it, I get four times false.
> ???
>
> Tester

Maybe you have one of those weird Windows computers?
On Mac OS 10.8.2, Maple 16.02, I can copy/paste this:

assume( a > 0, -a < b,b < a, -a < c,c < a, -a < d,d < a );
is( a > 0 ); is( b^2 <a^2 ); is( c^2 <a^2 ); is( d^2 <a^2 );

and get 4 times true.

[Tester]

Yes, same here now. Strange. Weird. Bizarre.
I do have one of those weird Windows computers indeed.
But who doesn't?

Anyway, now there's another little thing:
This
assume( a > 0, -a < b,b < a, -a < c,c < a );
is( a > 0 ); is( b^2 <a^2 ); is( c^2 <a^2 ); is( b*c <a^2 )
produces
true
true
true
FAIL

When, as a test, I explicitly add an assumption like
b*c < a^2 ,
Maple goes into an infinite loop.
So, any idea how to help Maple understand that
b*c < a^2
follows from
assume( a > 0, -a < b,b < a, -a < c,c < a )?

Tester

[Mate]

On Feb 12, 3:32 pm, "Tester" <tes...@hotmail.not> wrote:
> A N Niel <ann...@nym.alias.net.invalid> wrote:
>
>
>
>
>
>
>
>
>

> > In article <5119f390$0$3107$ba620...@news.skynet.be>, Tester

The assume facility is very weak for expressions in more than one
variables.
In your case there is a workaround:

assume( a > 0, -1 < t,t < 1, -1 < s,s < 1 );
b:=t*a; c:=s*a;
is( a > 0 ); is( b^2 <a^2 ); is( c^2 <a^2 ); is( b*c <a^2 ) ;
==> all true.

Even for simple questions like:

assume(sin(t)=0):
is(sin(2*t)=0);

Maple fails.


P.S. What about this one? Does anybody know?

assume(Zeta(z)=0, Re(z)>0):
is(Re(z)=1/2);

[Tester]

Yes, VERY smart! Thank you very much.

Tester