[sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-22 Thread Dima Pasechnik
On 2014-07-16, slelievre wrote: > Robert Pollak wrote: > > Hello! >> >> I see the following wrong results: >> >> sage: x<2 and x<1 >> x < 2 >> sage: x<2 or x<1 >> x < 1 >> >> Is this just a syntax problem? How would I enter this correctly? >> > > The best way to manipulate logical combinati

[sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-18 Thread Robert Pollak
On Wednesday, July 16, 2014 10:25:03 AM UTC+2, I wrote: > > I see the following wrong results: > > sage: x<2 and x<1 > x < 2 > sage: x<2 or x<1 > x < 1 > I found a way to compute these with Sage: sage: qepcad(qepcad_formula.and_(x < 2, x < 1), vars='(x)') x - 1 < 0 sage: qepcad(qepcad_formul

Re: [sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-17 Thread P Purkayastha
http://trac.sagemath.org/ticket/14229 On Friday, July 18, 2014 12:28:18 AM UTC+8, Robert Pollak wrote: > > > Also, why do I need two steps here?: > > sage: solve([x==0, x!=1], x) > [[x == 0, -1 != 0]] > solve([x == 0, -1 != 0], x) > [x == 0] > > -- You received this message because you are subsc

Re: [sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-17 Thread Robert Pollak
Also, why do I need two steps here?: sage: solve([x==0, x!=1], x) [[x == 0, -1 != 0]] solve([x == 0, -1 != 0], x) [x == 0] -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send a

Re: [sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-17 Thread Robert Pollak
Am 17.07.2014 11:32, schrieb Robert Pollak: > In fact, I do not even know how to create the "and" situation. > The following should be "x<=2 and x>=0": > > sage: Polyhedron(ieqs=[(2,-1), (0,0)]).Hrepresentation() > (An inequality (-1) x + 2 >= 0,) Oops, mistake! This should be sage: Polyhedron(i

Re: [sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-17 Thread Robert Pollak
Am 16.07.2014 21:06, schrieb slelievre: > Robert Pollak wrote: > I see the following wrong results: > > sage: x<2 and x<1 > x < 2 > sage: x<2 or x<1 > x < 1 > > The best way to manipulate logical combination of inequalities might be > to use polyhedra. Looking at the document

Re: [sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-17 Thread Robert Pollak
Am 16.07.2014 20:41, schrieb Nils Bruin: > On Wednesday, July 16, 2014 1:25:03 AM UTC-7, robert.pollak wrote: > sage: x<2 and x<1 > x < 2 > sage: x<2 or x<1 > x < 1 > > That's because "and" and "or" are program flow constructs in python, as > they are in C (they have "shortcut eval

[sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-16 Thread Nils Bruin
On Wednesday, July 16, 2014 11:41:49 AM UTC-7, Nils Bruin wrote: > That's because "and" and "or" are program flow constructs in python, as > they are in C (they have "shortcut evaluation" behaviour. They are > equivalent to > > (x<2) if bool(x<2) else (x<1) > > and > > (x<2) if not(bool(x<2)) el

[sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-16 Thread slelievre
Robert Pollak wrote: Hello! > > I see the following wrong results: > > sage: x<2 and x<1 > x < 2 > sage: x<2 or x<1 > x < 1 > > Is this just a syntax problem? How would I enter this correctly? > The best way to manipulate logical combination of inequalities might be to use polyhedra. It's

[sage-support] Re: Simplifying combinations of atomic inequalities

2014-07-16 Thread Nils Bruin
On Wednesday, July 16, 2014 1:25:03 AM UTC-7, robert.pollak wrote: > > Hello! > > I see the following wrong results: > > sage: x<2 and x<1 > x < 2 > sage: x<2 or x<1 > x < 1 > That's because "and" and "or" are program flow constructs in python, as they are in C (they have "shortcut evaluati