+bimap *create_bimap_helper(sokoban_screen *screen)
+{
+ int varcount = 0;
+ sokoban_screen *r;
+ xy_bddvar_map *xybdd = NULL;
+ bddvar_xy_map *bddxy = NULL;
+ for(r=screen; r != NULL; r = (sokoban_screen *)(r->hh.next)){
+ xy_bddvar_map *f = NULL;
+ f = (xy_bddvar_map *)malloc(sizeof(xy_bddvar_map));
+ memset(f, 0, sizeof(xy_bddvar_map));
+ f->key.x = r->coord.x;
+ f->key.y = r->coord.y;
+ f->value.var[0] = varcount;
+ f->value.var[1] = varcount + 1;
+ f->value.var[2] = varcount + 2;
+ HASH_ADD(hh, xybdd, key, sizeof(xy), f);
+
+ for (int i = 0; i <3; i++){
+ bddvar_xy_map *t = NULL;
+ t = (bddvar_xy_map *)malloc(sizeof(bddvar_xy_map));
+ memset(t, 0, sizeof(bddvar_xy_map));
+ t->key = varcount + i;
+ t->value.x = r->coord.x;
+ t->value.y = r->coord.y;
+ HASH_ADD(hh, bddxy, key, sizeof(int), t);
+ }
+ varcount = varcount + 3;
+ }
+ bimap *bm = NULL;
+ bm = (bimap *)malloc(sizeof(bimap));
+ bm->f = xybdd;
+ bm->t = bddxy;
+ return bm;
+}
+