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: There is at least one x_7 for which x_7 is curious or x_7 will go running. For all x_7, if x_7 goes running, then x_7 is writing a letter. For all x_7, x_7 is not curious or x_7 is a janitor. For all x_7, x_7 will write a letter if and only if x_7 is a janitor.
There is at least one x_7 for which x_7 will go running or x_7 is a janitor can be inferred via the existential resolution rule. For all x_7, if x_7 writes a letter, then x_7 is a janitor can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 were a janitor, then x_7 is writing a letter can be inferred via the universal biconditional elimination rule.