University of David
Archive
/
RSS
September 19
Since, with the concept of a function, one moved away from the necessity of having an analytic construction, and began to take its essence to be a tabular collection of values associated to the values of one or several variables, it became possible to take the concept to include functions which, due to conditions of an arithmetic nature, have a determinate sense only when the variables occurring in them have integral values, or only for certain value-combinations arising from the natural number series. For intermediate values, such functions remain indeterminate and arbitrary, or without any meaning.14 [35, p. 706]
1850 paper by Eisenstein
http://arxiv.org/pdf/1209.3657v1.pdf