Mixed integer and real problems

[bobot]

The type is_int can be specified on the variables and on the environment. But only integer variables are usable in an integer environment (cf invariant _01__check_type). Why this duplication? Is it possible to mix integer and real variable in the same problem?

[iguerNL]

Currently, is_int flags are only used for debug/invariants checks. I added them to eventually put some algorithms dedicated to integers (eg. branch and bound) in the future. I didn't think to mixed integer/real problems when I designed the library.