[SCIP] Solving LP again in the pricerredcost

[Shin, Jungeun]

Hi SCIPers,

I would like to ask how we can solve LP relaxation again in the pricerredcost after adding local constraints. 

I know this is a weird question, but here is my issue.  I am working on Branch-cut-price model using pyscipopt interface. 

I have a branching scheme similar to Ryan-foster (not the same) and need to create nodes and add respective constraints to each node locally using “SCIPaddConsnode” within the branchrule module.

However, there is some problem using this addConsnode in pyscipopt package which raises a segfault error. (I have asked this issue to Pyscipopt community on github, but it doesn’t seem to be a known issue that can be resolved quickly.)

I am trying to use kind of hacky way of applying the branching scheme without using addConsnode,  by adding constraints in the pricerredcost and solve LP again to get the updated dual solutions to compute subproblem. 

Long story in short,
1) Can we solve LP master problem again in the pricerredcost?

2) Can we use branching scheme like a Ryanfoster rule without using addConsnode? 

Jungeun