x0: word used to test the efficiency of a lujvo-building computer program. (nullary predicate)
Also anything longer than four syllables of "blo" (rafsi of the gismu bloti). The test of building lujvo like these helps distinguish between lujvo building algorithms in polynomial time from those in exponential time, especially given that bloti has five rafsi. For example, the sozysozbot jvozba will take a significant amount of time to build the lujvo from eight bloti. See also: bloti.