[SCIP] Does node expansion automatically update pseudo-costs using parent LP?

[Gui Jun Ye]

Dear all,

I intend to use a custom branching rule, then switch to the default 
reliability branching rule after a restart. I would like reliability 
branching to be able to use the pseudo-costs learned in the custom rule 
(from LP of parent node; no strong branching is performed in the custom 
rule).

Do I need to call `SCIPupdateVarPseudocost()` explicitly in the custom 
branching rule, or does SCIP already update the pseudo-cost after the LP 
solution of the current node?

Looking at Doxygen, not all branching rules refer to 
`SCIPupdateVarPseudocost()` ( e.g. `branch_relpscost.c` uses it after 
strong branching gives more information), which suggests that the 
pseudo-cost update from LP objective value occurs elsewhere; however if 
such an update exists it seems to not use this API.

I'm leaning towards the belief that this pseudo-cost update is being 
handled by SCIP after node expansion, but I would like confirmation that 
this is the case. I would also like to verify is that pseudo-costs are 
kept after a restart using `SCIPrestartSolve()`.

Many thanks,

Jim