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_13, x_13 is happy or x_13 will go running. Sarah is running if and only if John is a musician. Sarah is happy if and only if John is a musician.
If Sarah goes running, then John is a musician can be inferred via the biconditional elimination rule. If Sarah were happy, then John is a musician can be inferred via the biconditional elimination rule. If John were a musician, then Sarah is running can be inferred via the biconditional elimination rule. If John were a musician, then Sarah is happy can be inferred via the biconditional elimination rule.