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 snowing. Linda is not a writer. Linda is a writer if and only if Susan is playing tennis.
It is snowing and Linda is not a writer can be inferred via the conjunction rule. Linda is not a writer and it is snowing can be inferred via the conjunction rule. If Linda were a writer, then Susan is playing tennis can be inferred via the biconditional elimination rule. If Susan plays tennis, then Linda is a writer can be inferred via the biconditional elimination rule. Susan is not playing tennis can be inferred via the biconditional elimination rule.