This paper presents four asymptotic conditions of smooth worldlines in
Minkowski space that are often used in special relativistic particle
dynamics. (A) Permanency with respect to an observer's time. (B) Perma
nency with respect to the proper time. (C) Finiteness of the gamma fac
tor. (D) Intersection with the light cone of any apex. The conditions
(B) and (D) are free from observers and it is verified that (A) and (C
) are invariant conditions for all inertial observers. To examine the
inclusion relations between (A), (B), (C) and (D), some inclusion rela
tions are proved and some are denied by counter examples. Then the con
cluding Venn diagram is obtained. Such researches must interest theore
tical physicists who unintentionally use one or plural number of these
conditions.