Re: [Axiom-mail] Solving inequalities
Ralf Hemmecke <[email protected]>
| Newsgroups | gmane.comp.mathematics.axiom.general,gmane.comp.mathematics.axiom.user |
|---|---|
| Message-ID | <[email protected]> |
>>> I'm trying to solve an inequality of the following form: >>> >>> find all values of x such that f(x) > 1, >>> where f(x) is an `Expression Integer' >>> >>> `solve' and `radicalSolve' are apparently not helpful here. Any idea on >>> how to achieve this? >> For polynomial f this can be done using "cylindrical algebraic decompositions" >> (CADs). Quite a bit of this is actually implemented by Renaud Rioboo, see >> AxiomContributions on MathAction. Unfortunately, some pieces are missing in >> order to solve inequalities. >> >> If you were able to fill the gaps, this would be really great. > > (Sorry for the late reply.) > > Actually, I'm not a mathematician and I'm afraid I wouldn't be able to > contribute to it without attending tens of hours of classes on that > topic. ;-) The problem is, as Martin has already pointed out, that your problem is undecidable if you do not restrict f to a certain class of functions (like for example polynomial functions). So nobody will be able to write a general solver for your problem. Could you specify they type of functions more clearly, ie, replace "Expression Integer" to some smaller class of functions? Ralf