tcanaca fu'ivla

x₁ is the node of present concern/is the current position in graph x₃ (not necessarily oriented; notice the terbri number), connected (possibly indirectly) to/with other nodes x₂ (possibly incomplete set) via (oriented) paths x₄

"Current position" is in thought. See also: grafu, tcanaba, tcanapu.

jbovlaste

In notes:

tcanaba: x₁ (node/vertex/station) is forward of/along from x₂ in oriented graph x₃ (graph with orientation) using oriented edge path x₄ (ordered sequence of ordered pairs). The path from x₂ to x₁ runs along/is coparallel with/downstream of the orientation on x₃ along path x₄.
tcanapu: x₁ (node/vertex/station) is backward of/along from x₂ in oriented graph x₃ (graph with orientation) using oriented edge path x₄ (ordered sequence of ordered pairs; oriented edges). The path from x₂ to x₁ along the (now-unoriented version of the) edges used in x₄ is counter/against/upstream of the orientation of x₃ (and/or given by the oriented version of x₄).