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: Mary is playing squash if and only if Patricia is a bartender. If Patricia were a bartender, then Mary is playing squash.
If Mary plays squash, then Patricia is a bartender can be inferred via the biconditional elimination rule. If Patricia were a bartender, then Mary is playing squash can be inferred via the biconditional elimination rule.