Since my model has one exponential set of constraints I opted to use a Branch&Cut and add them as they are needed. I have a separation procedure which works on both, integers and fractional solutions to check if one or more constraints of this set are being violated.

If in the separation procedure I found one or more violated constraints and add them into the model, feasible integer solutions may be removed from the feasible space, so I by definition I should use the

**LazyConstraintCallbackI**, but this callback is only called when candidate feasible (integer) solutions are found. I wanted to also being able to analyze the fractional solutions found along the way.

By definition I shouldn't use

**UserCutCallbackI**since the cut would remove part of the feasible space of solutions, so which callback should I use to implement this?

Thanks.