Enea Zaffanella wrote:
In various places in the source files, we have assertions requiring that matrices (of constraints and generators) have a number of columns <> 1. These assertions can be violated by the following code,
[...]
There are three ways to solve such a situation:
[Two kludges removed ;-)]
- we remove all assertions of this kind. Non-empty 0-dim constraint
systems will be legal and will contain constraints that are either always false (like the one above) or always true (like the positivity constraint 1 >= 0). Note that the representation of the empty polyhedron needs not to be changed, i.e., we just look at the status flag and do not need to explicitly insert have a matrix for the always false constraint.
The easiest-to-implement solution is 1. The cleanest one, in my opinion, is solution 3. Here are some other reasons:
[Good reasons removed]
Is anyone foreseeing other problems for such a change ?
I am very much in favor of solution 3. In fact, while developing the initial draft of the Prolog interface I have come across the same problems Enea pointed out and I made also some choices that are in the direction of solution 3 above.
Elisa, can you give this problem (i.e., seeing whether solution 3 is feasible) the highest priority? Ciao,
Roberto