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: It is not raining. For all y_1, y_1 will take a plane if and only if y_1 will go running. It is raining if and only if Mary is taking a plane.
If it rains, then Mary is taking a plane can be inferred via the biconditional elimination rule. If Mary takes a plane, then it is raining can be inferred via the biconditional elimination rule. Mary is not taking a plane can be inferred via the biconditional elimination rule. For all y_1, if y_1 takes a plane, then y_1 is running can be inferred via the universal biconditional elimination rule. For all y_1, if y_1 goes running, then y_1 is taking a plane can be inferred via the universal biconditional elimination rule.