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: David is cooking or Jennifer is a taxi driver. For all z, z is a taxi driver if and only if z will climb a mountain. David is not cooking.
Jennifer is a taxi driver can be inferred via the disjunctive syllogism rule. If Jennifer listens to a song, then David is cooking can be inferred via the rewriting rule. For all z, if z were a taxi driver, then z is climbing a mountain can be inferred via the universal biconditional elimination rule. For all z, if z climbs a mountain, then z is a taxi driver can be inferred via the universal biconditional elimination rule.