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_10, if x_10 were an office clerk, then x_10 is a nurse. For all x_10, if x_10 plays squash, then x_10 is not an electrician. There is at least one x_10 for which if x_10 were a nurse, then x_10 is playing squash. For all x_10, x_10 is an electrician.
For all x_10, x_10 will not play squash can be inferred via the universal modus tollens rule. There is at least one x_10 for which if x_10 were an office clerk, then x_10 is playing squash can be inferred via the existential transitivity rule.