+static inline bool is_zero(double z)
+{
+ return fabs(z) < 1e-6;
+}
+
+static inline bool is_equal(double x, double y)
+{
+ return is_zero(x-y);
+}
+
+void debug(const char *msg, ...) FORMAT_CHECK(printf, 1, 2);
+void warn(const char *msg, ...) FORMAT_CHECK(printf, 1, 2);
+void die(const char *msg, ...) FORMAT_CHECK(printf, 1, 2) NONRET;
+
+// This one is called during execution of commands and propagated as an exception
+void err(const char *msg, ...) FORMAT_CHECK(printf, 1, 2) NONRET;
+