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: For all x_11, x_11 will not go running. For all x_11, x_11 is sad. For all x_11, x_11 is happy or x_11 will play a game. For all x_11, x_11 is happy if and only if x_11 will go running.
For all x_11, if x_11 were happy, then x_11 is running can be inferred via the universal biconditional elimination rule. For all x_11, if x_11 goes running, then x_11 is happy can be inferred via the universal biconditional elimination rule. For all x_11, x_11 is not happy can be inferred via the universal biconditional elimination rule.