Limiting model to select one technology per a specified period

[Hamed Kouchaki Penchah]

There are 9 mining technologies. I'd like to have one mining technology out of these 9 technologies per a specified period. It's not possible to have more than one mining technology during each period. Here is a simple user constraint for just two technologies that I wrote. But it's not working, and the model using both mining technologies. I'd appreciate it if you could help me with writing this user constraint or referring to an example in demo models.

[Antti-L]

The condition that "only one mining technology out of 9 technologies" should operate in a specified period, is not a convex condition and thus cannot be modeled as an endogenous decision, unless you resort to a MIP formulation. But you can of course model it exogenously, using e.g. ACT_BND or PRC_AOFF.