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: Jessica is playing squash if and only if Elisabeth is an astronaut. For all x_10, if x_10 were an astronaut, then x_10 is a cashier.
If Jessica plays squash, then Elisabeth is an astronaut can be inferred via the biconditional elimination rule. If Elisabeth were an astronaut, then Jessica is playing squash can be inferred via the biconditional elimination rule.