extern bool get_is_floor(int x, int y);
extern void set_floor(int x, int y);
-extern bool build_tunnel(int row1, int col1, int row2, int col2);
-extern bool build_tunnel2(int x1, int y1, int x2, int y2, int type, int cutoff);
+extern bool build_tunnel(POSITION row1, POSITION col1, POSITION row2, POSITION col2);
+extern bool build_tunnel2(POSITION x1, POSITION y1, POSITION x2, POSITION y2, int type, int cutoff);