Returns true if and only if u is a predecessor of v.

var g = new HashDigraph[Int]
g.add_arc(1, 3)
assert g.is_predecessor(1, 3)
assert not g.is_predecessor(3, 1)

Property definitions

graph $ Digraph :: is_predecessor
	# Returns true if and only if `u` is a predecessor of `v`.
	#
	# ~~~
	# var g = new HashDigraph[Int]
	# g.add_arc(1, 3)
	# assert g.is_predecessor(1, 3)
	# assert not g.is_predecessor(3, 1)
	# ~~~
	fun is_predecessor(u, v: V): Bool do return has_arc(u, v)
lib/graph/digraph.nit:381,2--389,58