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: Linda is cooking if and only if Robert is a lawyer. James is reading a book if and only if Robert is a lawyer. James is not reading a book.
If Linda cooks, then Robert is a lawyer can be inferred via the biconditional elimination rule. If James reads a book, then Robert is a lawyer can be inferred via the biconditional elimination rule. If Robert were a lawyer, then Linda is cooking can be inferred via the biconditional elimination rule. If Robert were a lawyer, then James is reading a book can be inferred via the biconditional elimination rule. Robert is not a lawyer can be inferred via the biconditional elimination rule.