First, I will define the activities and activities dependencies associated to this process.
For example, we can consider the following list of activities involved in the purchase-to-pay process:
'Create Purchase Order Line', 'Confirm Purchase Order Line', 'Add Payment Line to Purchase Order Line', 'Mark Purchase Order Line as Complete',  'Print Purchase Order'
There is also a dependency between the two last activities: 'Complete Purchase Order'. 
The Log Skeleton model contains several constraints associated with the activities involved in this process.
For example, we can consider that the following are the direct dependencies among some of these activities:
'Complete Purchase Order' -  'Print Purchase Order',  'Confirm Purchase Order Line' -  'Mark Purchase Order Line as Complete',  'Add Payment Line to Purchase Order Line' -  'Mark Purchase Order Line as Complete'
Then, we can define a set of constraints related with the dependencies previously defined. For example, if an activity occurs before another one, then there is no constraint for the first one and also for the second one. 
For our purchase-to-pay process, the activities involved are Create Purchase Order Line, Confirm Purchase Order Line, Add Payment Line to Purchase Order Line, Mark Purchase Order Line as Complete, Print Purchase Order. There are several constraints between these activities. For example:
'Complete Purchase Order'
is a constraint such that any time 'Print Purchase Order' occurs, then so does 'Complete Purchase Order'. 
Can you generate Log Skeleton model for an hypothetical Purchase-to-pay process involving the following set of activities:  'Create Purchase Order Line', 'Confirm Purchase Order Line', 'Add Payment Line to Purchase Order Line', 'Mark Purchase Order Line as Complete', 'Print Purchase Order'. Besides, consider that there are some direct dependencies among some of these activities. For example, we can consider that the following are the direct dependencies among some of these activities:  'Complete Purchase Order' -  'Print Purchase Order',  'Confirm Purchase Order Line' -  'Mark Purchase Order Line as Complete',  'Add Payment Line to Purchase Order Line' -  'Mark Purchase Order Line as Complete'. Besides, there is also a set of constraints related with the dependencies previously defined. For example, if an activity occurs before another one, then there is no constraint for the first one and also for the second one. 
Can you generate Log Skeleton model for an hypothetical Purchase-to-pay process involving the following set of activities:  'Create Purchase Order Line', 'Confirm Purchase Order Line', 'Add Payment Line to Purchase Order Line', 'Mark Purchase Order Line as Complete', 'Print Purchase Order'. Besides, consider that there are some direct dependencies among some of these activities. For example, we can consider that the following are the direct dependencies among some of these activities:  'Complete Purchase Order' -  'Print Purchase Order',  'Confirm Purchase Order Line' -  'Mark Purchase Order Line as Complete',  'Add Payment Line to Purchase Order Line' -  'Mark Purchase Order Line as Complete'. Besides, there is also a set of constraints related with the dependencies previously defined. For example, if an activity occurs before another one, then there is no constraint for the first one and also for the second one. 
Can you generate Log Skeleton model for an hypothetical Purchase-to-pay process involving the following set of activities:  'Create Purchase Order Line', 'Confirm Purchase Order Line', 'Add Payment Line to Purchase Order Line', 'Mark Purchase Order Line as Complete', 'Print Purchase Order'. Besides, consider that there are some direct dependencies among some of these activities. For example, we can consider that the following are the direct dependencies among some of these activities:  'Complete Purchase Order' -  'Print Purchase Order',  'Confirm Purchase Order Line' -  'Mark Purchase Order Line as Complete',  'Add Payment Line to Purchase Order Line' -  'Mark Purchase Order Line as Complete'. Besides, there is also a set of constraints related with the dependencies previously defined. For example, if an activity occurs before another one, then there is no constraint for the first one and also for the second one. 
Can you generate Log Skeleton model for an hypothetical Purchase-to-pay process involving the following set of activities:  'Create Purchase Order Line', 'Confirm Purchase Order Line', 'Add Payment Line to Purchase Order Line', 'Mark Purchase Order Line as Complete', 'Print Purchase Order'. Besides, consider that there are some direct dependencies among some of these activities. For example, we can consider that the following are the direct dependencies among some of these activities:  'Complete Purchase Order' -  'Print Purchase Order',  'Confirm Purchase Order Line' -  'Mark Purchase Order Line as Complete',  'Add Payment Line to Purchase Order Line' -  'Mark Purchase Order Line as Complete'. Besides, there is also a set of constraints related with the dependencies previously defined. For example, if an activity occurs before another one, then there is no constraint for the first one and also for the second one.