The output files from cramer4.c are
ordered4tuples --- contains 4-tuples in the form a0 <= a1 <= a2 <= a3, but there may be repetition. This file is further processed by "lexicographic4.c" series --- Contains the 4-tuples that fall into infinite series, arising from the case when det C does not depend on m0. (There can be overlap with other files. The same 4-tuple can appear in several ways, once in a series or on its own). multiples --- also comes from the case where det C does not depend on m0. Here we don't get a series because the shift vector is a multiple of [a1,a2,a3] and therefore most 4-tuples in this would-be series violate the relatively prime condition. There is nothing new here --- all are found in final4tuples already. zerozero --- output from cramer4.c in the case where d0/detC can be made 0/0 by a careful choice of m0. This file is always empty.