zatra'i lujvo

r1=z1 exists over interval r2.

r1=z1 is r2 years/days etc. old. Not restricted to biological forms. Cf. zasti, ranji, temci, ditcu, jbena, morsi, cfari, fanmo, jmive.

In notes:

citmau
z1=c1 is younger than z2 by amount z4.
citrai
t1=c1 is youngest among t4.