In some cases, a valid demes graph will have a pulse with the source coming from a population that ends at that same time. Allowing these corner cases requires changing the order of discrete demographic events, so that operations that marginalize a deme (splits and mergers) occur after operations that could include such demes (pulses and admixtures).
In some cases, a valid demes graph will have a pulse with the source coming from a population that ends at that same time. Allowing these corner cases requires changing the order of discrete demographic events, so that operations that marginalize a deme (splits and mergers) occur after operations that could include such demes (pulses and admixtures).