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 cooking or Susan is not a mechanic. Susan is a mechanic. For all x_17, x_17 is a bartender if and only if x_17 will cook.
If Susan were a mechanic, then Richard is cooking can be inferred via the rewriting rule. For all x_17, if x_17 were a bartender, then x_17 is cooking can be inferred via the universal biconditional elimination rule. For all x_17, if x_17 cooks, then x_17 is a bartender can be inferred via the universal biconditional elimination rule.