x1 is any child of the first child of the first child of ... the first child of x2, where the graph geodesic through the ancestorship-directed family tree from x1 to x2 is of length (x3) + 1 (li; x3 must be a nonnegative integer or positive infinity), and where "first" is according to (partial) ordering rule x4 (default: chronological order of birth per successive generation within the given lineage; other restrictions on legitimacy etc. may be specified here as well).
Respects the direction (possibly asymmetry) of the relation so that the graph geodesic distance from A to B may not equal that of from B to A (and either of them may not be defined at all or may be infinite); path-linking is as in ".utka". Other properties are as in or analogous to those of "1), where "first" is according to (partial) ordering rule x4 (default: chronological order of birth per successive generation within the given lineage; other restrictions on legitimacy etc. may be specified here as well).">pavmompazy'utka'ypanzi". Due to restrictions on x3, x1 and x2 must be mutually distinct. As an example: If Queen Elizabeth II of the UK/Commonwealth is x2 and chronological order of birth for legitimate children (gender-neutral primogeniture on legitimate descent) is used as x4, then the set of possible x1s includes (and, as of 9 May A.D. 2019, is equal to the set of) all of the children of Elizabeth II, the legitimate children of her son Charles (William, Harry), and all of William's children (George, Charlotte, Louis); notice that the descendants of Elizabeth II not via Charles are excluded, as are any descendants not by William (including Harry's children); the next generation of possible x1s will be (supposing that they come to exist) the children of George (the first-born legitimate son of William first-born legitimate son of Charles first-born legitimate son of Queen Elizabeth II) but not the descendants of William not by George; the fact that all of the intermediate steps are male is mere coincidence; this selbri in this example is a generalization of how the title "prince" is automatically bestowed in this line (excluding by marriage), at present, except for those who are granted princehood by virtue of being the children of the sons of the sovereign - in particular, if "su'e re" is submitted as x3, then the rules match at present (with the aforementioned exception) because the automatic granting of the title halts with the children of William (who possess the longest possible graph geodesics to the queen by this relation).