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: Joseph is happy if and only if Elisabeth is running. For all x_14, x_14 is happy.
If Joseph were happy, then Elisabeth is running can be inferred via the biconditional elimination rule. If Elisabeth goes running, then Joseph is happy can be inferred via the biconditional elimination rule.