x1 = t1 is the elapsed time required for decaying/diminishing/reducing/shrinking population x2 = g1 to decrease in number by a factor of exactly/approximately 1/e^(x3) from that which is considered to be the initial population size, where e is the natural exponential base and x3 [li; default: 1] is a real number, according to standard/under condition/by model/in experiment x4; x1 is the one-(e^(x3))-th-life of population/sample x2; the (approximate) (x3)-th one-e-th-ing/e-fold decrease(/increase) of population x2 takes approximately x1 (time).
The experimental gismu tezda is used in the veljvo of this word. Many of the veljvo terbri can be derived from those which are present. This word may refer to a duration that is statistical (for large samples, the average time required for half of the population to probably disappear/become invalid), ideal (guaranteed rather than statistical), or experimental (in a given trial, some number was recorded on a stopwatch when the count decreased by half). This word is analogous not only to half-life (default sense) but also to doubling time (if x3 is filled by -1). See also: grixabybi'otei, grixonbybi'otei.