#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
+#include <errno.h>
#define D3 3
double magnD(const double pq[D3]);
void xprod(double r[D3], const double a[D3], const double b[D3]);
+void flushoutput(void);
+void diee(const char *what);
+
#define FOR_COORD(k) \
for ((k)=0; (k)<D3; (k)++)