[Coin-lpsolver] Querying the feasible bounds

[Lou Hafer]

Spencer,

	To expand a bit on Matt's answer: Essentially, you're asking the solver
to infer tighter bounds by looking at the interactions between your constraints.
This is what a presolve does --- analyses the constraint system and modifies
it (usually, simplifies it) so that the inferences are explicit in the system.

	Over in AI, various techniques that OR people apply in presolve are used
(often with more persistence) in constraint propagation.  Arc consistency
(generalised as k-consistency) is one such technique.

	You can think of cutting planes as inferring consequences of
integrality.

	Bottom line, though, is that inference is not free.
	
							Lou