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Is there a combination of parameter settings so that the search tree only contains "simple" node types, i.e. not SCIP_NODETYPE_{PROBINGNODE, DEADEND, JUNCTION, PSEUDOFORK, FORK, SUBROOT, REFOCUSNODE}? Even if it means disabling some functionality.

I'm also not really sure about what the different node types really mean, so any pointers to documentation would also be very useful.

user2660278
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The meaning of the different node types is explained here. If you have a closer look, you will understand that those types reflect the internal organization of the tree. They necessarily occur during tree search and cannot be skipped via parameters.

If you insist: setting limits/nodes = 1 will process only the root node of SCIP, and the tree will only consist of a focus node and its 2 children.

Gregor
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  • My question is then more basic. What is a fork, subroot, junction, etc.? I have read that file and do not understand it still. Why do they necessarily occur in the tree search. For example is a fork when the LP relaxation for the node is solved and there are rows and columns added added (e.g. due to cuts) but the node has not been branched yet? Why would this be useful? I can't seem to find these concepts in MIP literature. – user2660278 Jul 08 '19 at 08:23
  • It is all about keeping the data between consecutive nodes consistent. The good news: A normal MIP tree search only requires the five types focus, fork, child, sibling, and leaf (plus probing nodes). No junctions or pseudo-forks are created unless you start playing with the LP solve frequency. Users usually do not access the tree, what exactly are you trying to achieve? – Gregor Jul 08 '19 at 19:11