What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: There is at least one x_7 for which x_7 will go running if and only if x_7 will play a game. For all x_7, x_7 will go running or x_7 will not read a book. For all x_7, x_7 will read a book or x_7 will play a game.
For all x_7, if x_7 reads a book, then x_7 is running can be inferred via the universal rewriting rule. There is at least one x_7 for which if x_7 goes running, then x_7 is playing a game can be inferred via the existential biconditional elimination rule. There is at least one x_7 for which if x_7 plays a game, then x_7 is running can be inferred via the existential biconditional elimination rule.