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: For all x_22, x_22 is a lawyer or x_22 is an astronaut. For all x_22, if x_22 were an astronaut, then x_22 is sad. If Karen were sad, then John is taking a plane. For all x_22, if x_22 were a lawyer, then x_22 is sad.
For all x_22, x_22 is sad can be inferred via the universal disjunction elimination rule.