x1 is old/familiar/well-known to observer x2 in feature x3 (ka) by standard x4.
This can cover both meanings of old. Old in years, i.e. age, can be conveyed through x2 = the world, life, existence (= loi nu zasti); in usage this has been a common default for ellipsis. However slabu is not the opposite of 'young' (= nalci'o, tolci'o), but the opposite of 'new' (= tolni'o); also ancient (= tcesau), age (= nilsau); x2 is used to x1 (= selsau for reordered places); historic/historical (= cirsau, cirselcedra; also vaipru). (cf. clani, citno, cnino, se djuno; not the opposite of citno, djuno)