do
return t != self.element and self.tos.has(t)
end
+
+ # The length of the shortest path to the root of the poset hierarchy
+ fun depth: Int do
+ if direct_greaters.is_empty then
+ return 0
+ end
+ var min = -1
+ for p in direct_greaters do
+ var d = poset[p].depth + 1
+ if min == -1 or d < min then
+ min = d
+ end
+ end
+ return min
+
+ end
end