This study is based on a mathematical model for the life table survivorship function developed by the author, "the form of which has been logically arrived at in a manner such that the simple but the well known constraints of the life table functions can be met by the model.  There are basically three parameters in the model which can be estimated by the method of least squares after the variables are subjected to appropriate transformations.  The characteristics of these parameters have been investigated in this paper which [makes] it readily apparent that the model can provide good approximations to a wide variety of life tables."  (summary in FRE, ITA)