E. Bolker describes his work on the Finite Radon Transform ([1987](//ams.org/mathscinet-getitem?mr=88b:51009)) as originally a deliberate (and successful) effort to gain insight into the continuous namesake(s). Its influence can be seen in the “Bolker condition” of Guillemin & Sternberg ([1979](//ams.org/mathscinet-getitem?mr=82b:58087)).