lib(probing_for_scheduling)


    This is a complete search method for resource-constrained scheduling 
    problems
    
    The user interface is similar to the cumulative constraint, with a 
    list of task start times, durations and resources; and a maximum 
    resource limit.  There is one extra argument, a cost function which 
    is to be minimised. 
    
    Probing for scheduling differs radically from the cumulative constraint
    because it includes a search routine.  In its behaviour it is an
    optimisation procedure and not simply a constraint which enforces 
    consistency. 
    
    The search is focussed towards an optimal vlaue of the cost function.
    
    

