tsutre lujvo

x1=m1=r1 measures x2=m2 meters in its third longest direction x3=m3=r2 by measurement standard x4=m4.

x1 rotsu is not asserted, which is why rotsu3 is absent. Cf. clatre, gantre

In notes:

clatre
x1=m1=c1 measures x2=m2 meters in its longest direction x3=m3=c2 by measurement standard x4=m4.
gantre
x1=m1=g1 measures x2=m2 meters in its second longest direction x3=m3=g2 by measurement standard x4=m4.