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: Richard is running or it is windy. Richard is not running. Patricia is rich if and only if Sarah is driving a car. Patricia is not rich.
It is windy can be inferred via the disjunctive syllogism rule. Richard is not running and Patricia is not rich can be inferred via the conjunction rule. Patricia is not rich and Richard is not running can be inferred via the conjunction rule. If Patricia were rich, then Sarah is driving a car can be inferred via the biconditional elimination rule. If Sarah drives a car, then Patricia is rich can be inferred via the biconditional elimination rule. Sarah is not driving a car can be inferred via the biconditional elimination rule.