name = 'flows/2' slug = '' description = '''\
flows(X, Y)
: the river X
flows to sea Y
.
The predicate should follow the flow from X
through different rivers
until it reaches a sea - for example, Drina flows into Save, which flows into Donau,
ending in the Black Sea:
?- flows('Drina', Y). Y = 'Black Sea'.
River data is given by the predicate
river(Name, FlowsToRiver, FlowsToLake, FlowsToSea, Length, Area, SourceLat, SourceLon, SourceElevation, MouthLat, MouthLon).''' hint = {}