x1 and x2 are path-linked by directed binary predicate x3 (ka) via intermediate steps x4 (ordered list; ce'o) in graph x5, such that (in the graph x5) both (A) no other node exists to which x2 is connected in/by the same way/direction/relation and (B) no other node exists to which x1 is connected in/by the opposite/(anti)symmetric/reversed way/direction/relation.
Equivalent to "x1 \, x fo x4 \, x .utkaro fi x3 gi'e se .utkaro fi x3^-1", where x3^-1 is binary relation/predicate x3 with the order of its two arguments exchanged (basically: "se"-converted). Multiple paths may connect x1 and x2. There may be peripheral branches extending from x2 which are acyclic (or cyclic) such that they contain a node which has a directed distance from x2 which exceeds that of any path from x1 to x2; it is just the case that for any path connecting x1 and x2 in either direction, x1 and x2 are root/leaf nodes thereof.