struct ao_hex_image *
ao_hex_load(char *filename, struct ao_sym **symbols, int *num_symbols);
+struct ao_hex_image *
+ao_hex_image_cat(struct ao_hex_image *a, struct ao_hex_image *b);
+
int
ao_hex_image_equal(struct ao_hex_image *a, struct ao_hex_image *b);