Indeterminate | _. |
The indeterminate _. is a numeric atom. It is provided to aid in dealing with NaN (not a number) in data from external sources, and should be removed from such data as soon as possible. The verb 128!:5 tests for _. . The only ways to create _. are as follows:
Primitives on arguments containing _. , that move data without interpreting the value, produce correct and consistent results. These include $ |. |: # , ,. [ ] { {. {: } }. }: . Other primitives on arguments containing _. may not produce correct or consistent results. In particular, the dyads < <: = >: > ~: -: <. >. do not produce consistent results on arguments containing _. , nor the verbs /: \: , nor the dyads i. i: e. -. , nor the monads ~. ~: , nor verbs defined in terms of these. Primitives on arguments not containing _. signal NaN error instead of producing _. .
0*_ , 0*__ , and 0%0 are all defined to be 0 . |