+#define PT *(PT_TO_PT)
+#define MM *(MM_TO_PT)
+#define CM *(CM_TO_PT)
+#define INCH *(INCH_TO_PT)
+#define BIGPOINT *(BIGPOINT_TO_POINT)
+#define CHAR *(CHAR_TO_PT)
+
+#else // mm
+
+#define INTERNAL_UNIT "mm"
+
+#define PT *(PT_TO_PT *PT_TO_MM)
+#define MM *(MM_TO_PT *PT_TO_MM)
+#define CM *(CM_TO_PT *PT_TO_MM)
+#define INCH *(INCH_TO_PT *PT_TO_MM)
+#define BIGPOINT *(BIGPOINT_TO_POINT *PT_TO_MM)
+#define CHAR *(CHAR_TO_PT *PT_TO_MM)
+
+#endif
+
+string print_dimen (Real);
+const Real point_constant = 1 PT;
+const Real inch_constant = 1 INCH;
+const Real cm_constant = 1 CM;
+const Real mm_constant = 1 MM;
+const Real bigpoint_constant = 1 BIGPOINT;
+
+#endif /* DIMENSIONS_HH */