x_{1} (node/vertex/station) is forward of/along from x_{2} in oriented graph x_{3} (graph with orientation) using oriented edge path x_{4} (ordered sequence of ordered pairs). The path from x_{2} to x_{1} runs along/is coparallel with/downstream of the orientation on x_{3} along path x_{4}.

Orientation is given from/by x3, so only an edge need be submitted if x3 is fully specified; if x3 is not fully specified, x4 can take the burden of specifying the orientation and subgraph of particular interest (namely, the two vertices x1 and x2, intervening vertices along the path, and the orientation of the given edges connecting them). Note that on an unoriented edge or along a cycle, x1 and x2 might be able to exchange places and/or be equal one another. x4 is an ordered sequence of ordered pairs; the first entry of each pair is the origin node, the second pair is the destination node; the path should probably be connected (so that the destination node of one pair is the origin node of the next, except possibly if it is the last such pair). x1 is not necessarily next (id est: forward adjacent of/from) x2, but it can be. Useful for pages, webpages, family relationships, utterances, etc. See also: grafu, tcanaca, tcanapu.

- tcanaca
- x
_{1}is the node of present concern/is the current position in graph x_{3}(not necessarily oriented; notice the terbri number), connected (possibly indirectly) to/with other nodes x_{2}(possibly incomplete set) via (oriented) paths x_{4} - tcanapu
- x
_{1}(node/vertex/station) is backward of/along from x_{2}in oriented graph x_{3}(graph with orientation) using oriented edge path x_{4}(ordered sequence of ordered pairs; oriented edges). The path from x_{2}to x_{1}along the (now-unoriented version of the) edges used in x_{4}is counter/against/upstream of the orientation of x_{3}(and/or given by the oriented version of x_{4}).