Compute the disjunctive bounds for a variable in a given scope.
Parameters:
var (VarData) – Variable for which to compute bound
scope (Component) – The scope in which to compute the bound. If not a
DisjunctData, it will walk up the tree and use the scope of the
most immediate enclosing DisjunctData.
Returns:
the tighter of either the disjunctive lower bound, the
variable lower bound, or (-inf, inf) if neither exist.