+/* Special object-state values - integers > 0 are object-specific */
+#define STATE_NOTFOUND -1 // 'Not found" state of treasures */
+#define STATE_FOUND 0 // After discovered, before messed with
+#define STATE_IN_CAVITY 1 // State value common to all gemstones
+
+/* Special fixed object-state values - integers > 0 are location */
+#define IS_FIXED -1
+#define IS_FREE 0
+
+/* Map a state property value to a negative range, where the object cannot be
+ * picked up but the value can be recovered later. Avoid colliding with -1,
+ * which has its own meaning. */
+#define STASHED(obj) (-1 - game.prop[obj])
+
+/*
+ * MOD(N,M) = Arithmetic modulus
+ * AT(OBJ) = true if on either side of two-placed object
+ * CNDBIT(L,N) = true if COND(L) has bit n set (bit 0 is units bit)
+ * DARK(LOC) = true if location "LOC" is dark
+ * FORCED(LOC) = true if LOC moves without asking for input (COND=2)
+ * FOREST(LOC) = true if LOC is part of the forest
+ * GSTONE(OBJ) = true if OBJ is a gemstone
+ * HERE(OBJ) = true if the OBJ is at "LOC" (or is being carried)
+ * LIQUID() = object number of liquid in bottle
+ * LIQLOC(LOC) = object number of liquid (if any) at LOC
+ * PCT(N) = true N% of the time (N integer from 0 to 100)
+ * TOTING(OBJ) = true if the OBJ is being carried */
+#define DESTROY(N) move(N, LOC_NOWHERE)
+#define MOD(N,M) ((N) % (M))
+#define TOTING(OBJ) (game.place[OBJ] == CARRIED)
+#define AT(OBJ) (game.place[OBJ] == game.loc || game.fixed[OBJ] == game.loc)
+#define HERE(OBJ) (AT(OBJ) || TOTING(OBJ))
+#define CNDBIT(L,N) (tstbit(conditions[L],N))
+#define LIQUID() (game.prop[BOTTLE] == WATER_BOTTLE? WATER : game.prop[BOTTLE] == OIL_BOTTLE ? OIL : NO_OBJECT )
+#define LIQLOC(LOC) (CNDBIT((LOC),COND_FLUID)? CNDBIT((LOC),COND_OILY) ? OIL : WATER : NO_OBJECT)
+#define FORCED(LOC) CNDBIT(LOC, COND_FORCED)
+#define DARK(DUMMY) (!CNDBIT(game.loc,COND_LIT) && (game.prop[LAMP] == LAMP_DARK || !HERE(LAMP)))
+#define PCT(N) (randrange(100) < (N))
+#define GSTONE(OBJ) ((OBJ) == EMERALD || (OBJ) == RUBY || (OBJ) == AMBER || (OBJ) == SAPPH)
+#define FOREST(LOC) CNDBIT(LOC, COND_FOREST)
+#define OUTSID(LOC) (CNDBIT(LOC, COND_ABOVE) || FOREST(LOC))
+#define INDEEP(LOC) ((LOC) >= LOC_MISTHALL && !OUTSID(LOC))
+#define BUG(x) bug(x, #x)
+#define MOTION_WORD(n) ((n) + 0)
+#define OBJECT_WORD(n) ((n) + 1000)
+#define ACTION_WORD(n) ((n) + 2000)
+#define SPECIAL_WORD(n) ((n) + 3000)
+#define PROMOTE_WORD(n) ((n) + 1000)
+#define DEMOTE_WORD(n) ((n) - 1000)