Thanks for posting this on the mailing list.
There's also a bug in the new `solve_univariate_inequalities`
```
In [2]: x = Symbol('x', positive=True)
In [3]: y = Symbol('y')
In [4]: solve_univariate_inequality(exp(x) > 1, x)
Out[4]: False
In [5]: solve_univariate_inequality(exp(y) > 1, y)
Out[5]: y > 0
```
This was caused by me by not taking care of the assumptions on the
variables. I'll fix it asap.
On 8 February 2014 07:28, Aaron Meurer <[email protected]> wrote:
> No, unfortunately, non-trivial relational assumptions like this are
> largely not implemented. As you may or may not know, the assumptions
> system in SymPy is currently in a bit of a mess. There are two
> assumptions systems, the "old" one, which is the one you used, and the
> "new" one, which uses ask() and Q.
>
> Neither can handle this, or really any kind of non-trivial
> Add.is_positive type assumption. It's not even clear to me at the
> moment how one would go about implementing such things.
>
> Aaron Meurer
>
> On Fri, Feb 7, 2014 at 11:47 AM, Patrick O'Neill <[email protected]> wrote:
>> Howdy folks,
>>
>> I'm a very new to sympy, and am stumped by the following error. Considering
>> the following code snippet:
>>
>> from sympy import *
>> print sympy.__version__
>> #'0.7.4.1-git'
>> epsilon,beta = var("epsilon,beta",positive=True)
>> (exp(epsilon*beta) - 1).is_positive # is None
>>
>> Sympy knows that beta and epsilon are positive, but seems not to know that
>> the exponential function takes positive quantities to quantities greater
>> than one. Is there a workaround for this issue, or is there something
>> fundamental to sympy's internals that makes this sort of deduction
>> impossible?
>>
>> I checked the mailing list, stack overflow and the issue tracker, and didn't
>> see anything pertaining to this question, but I admit I might not know what
>> I'm looking for.
>>
>> Thanks in advance!
>>
>> Cheers,
>> Pat.
>>
>>
>> On Fri, Feb 7, 2014 at 12:45 PM, Patrick O'Neill <[email protected]> wrote:
>>>
>>> Howdy folks,
>>>
>>> I'm a very new to sympy, and am stumped by the following error.
>>> Considering the following code snippet:
>>>
>>> from sympy import *
>>> print sympy.__version__
>>> #'0.7.4.1-git'
>>> epsilon,beta = var("epsilon,beta",positive=True)
>>> (exp(epsilon*beta) - 1).is_positive # is None
>>>
>>> Sympy knows that beta and epsilon are positive, but seems not to know that
>>> the exponential function takes positive quantities to quantities greater
>>> than one. Is there a workaround for this issue, or is there something
>>> fundamental to sympy's internals that makes this sort of deduction
>>> impossible?
>>>
>>> I checked the mailing list, stack overflow and the issue tracker, and
>>> didn't see anything pertaining to this question, but I admit I might not
>>> know what I'm looking for.
>>>
>>> Thanks in advance!
>>>
>>> Cheers,
>>> Pat.
>>
>>
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