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_13, x_13 is not an electrician or x_13 is a mechanic. For all x_13, if x_13 were curious, then x_13 is an electrician. There is at least one x_13 for which x_13 will sleep. For all x_13, if x_13 sleeps, then x_13 is an electrician.
There is at least one x_13 for which x_13 is an electrician can be inferred via the existential modus ponens rule.