[Symphony-tickets] [SYMPHONY] #128: node->feasibility_status ambiguity

[SYMPHONY]

#128: node->feasibility_status ambiguity
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 Reporter:  anh509       |      Owner:  tkr
     Type:  enhancement  |     Status:  new
 Priority:  normal       |  Milestone:
Component:  TreeManager  |    Version:  trunk (SVN)
 Keywords:               |
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 The stati of the nodes that are pruned by bound, (i.e. OVER_UB_PRUNED) is
 set to INFEASIBLE_PRUNED in line 1526 of tm_func.c with

 if (action[i] == PRUNE_THIS_CHILD_INFEASIBLE){
 child->feasibility_status = INFEASIBLE_PRUNED;}.

 Commenting this out preserves them. However, in the first place,
 I am not sure what is the logic behind setting the action of such nodes to
 PRUNE_THIS_CHILD_INFEASIBLE. It sounds more intuitive to set the it to
 PRUNE_THIS_CHILD_FATHOMABLE. (and keep RUNE_THIS_CHILD_INFEASIBLE) just
 for lp-infeasible nodes.

 This can be done in lp_wrapper.c line 1865. Currently, the last "else"
 sets the action for nodes that are pruned by termcodes "LP_D_OBJLIM" and
 "LP_D_UNBOUNDED" both to PRUNE_THIS_CHILD_INFEASIBLE. This could be
 clarified by adding "LP_D_OBJLIM" to line 1869.

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Ticket URL: <https://projects.coin-or.org/SYMPHONY/ticket/128>
SYMPHONY <http://projects.coin-or.org/SYMPHONY>
The SYMPHONY framework for parallel branch-and-cut algorithms.