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: James is not playing squash. James is playing squash if and only if James is a taxi driver. Robert is a soldier if and only if James is a taxi driver. For all x_7, x_7 is a bartender if and only if x_7 is a soldier.
If James plays squash, then James is a taxi driver can be inferred via the biconditional elimination rule. If Robert were a soldier, then James is a taxi driver can be inferred via the biconditional elimination rule. If James were a taxi driver, then James is playing squash can be inferred via the biconditional elimination rule. If James were a taxi driver, then Robert is a soldier can be inferred via the biconditional elimination rule. James is not a taxi driver can be inferred via the biconditional elimination rule. For all x_7, if x_7 were a bartender, then x_7 is a soldier can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 were a soldier, then x_7 is a bartender can be inferred via the universal biconditional elimination rule.