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: Patricia is not a taxi driver. It is sunny if and only if Patricia is a taxi driver. Linda is playing squash or it is not sunny. If Linda plays squash, then it is sunny.
If it is sunny, then Linda is playing squash can be inferred via the rewriting rule. If it is sunny, then Patricia is a taxi driver can be inferred via the biconditional elimination rule. If Patricia were a taxi driver, then it is sunny can be inferred via the biconditional elimination rule. It is not sunny can be inferred via the biconditional elimination rule.