void proc_set_sink (struct case_sink *);
struct casefile *proc_capture_output (void);
-bool procedure (bool (*proc_func) (struct ccase *, void *),
+bool procedure (bool (*proc_func) (const struct ccase *, void *),
void *aux);
bool procedure_with_splits (void (*begin_func) (const struct ccase *, void *),
bool (*proc_func) (const struct ccase *, void *),