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cumulative(+StartTimes, +Durations, +Resources, ++ResourceLimit)

Cumulative constraint on specified tasks.

StartTimes: List of start times for tasks (fd variables or integers)
Durations: List of duration for tasks (fd variables or integers)
Resources: List of resource uages by tasks (fd variables or integers)
ResourceLimit: Maximum amount of resource available (integer)

Description

A cumulative scheduling constraint. StartTimes, Durations and Resources are lists of equal length N of finite domain variable or integers. ResourceLimit is an integer. The declarative meaning is: If there are N tasks, each starting at a certain start time, having a certain duration and consuming a certain (constant) amount of resource, then the sum of resource usage of all the tasks does not exceed ResourceLimit at any time. The (ic/fd)_edge_finder and (ic/fd)_edge_finder3 libraries implementation of this predicate can provide stronger propagations.