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_15, x_15 will play a game if and only if x_15 is an astronaut. For all x_15, if x_15 takes a plane, then x_15 is not running. For all x_15, x_15 will not play a game. There is at least one x_15 for which x_15 is not a bartender or x_15 will go running. For all x_15, x_15 is a bartender or x_15 is an astronaut.
There is at least one x_15 for which x_15 is an astronaut or x_15 will go running can be inferred via the existential resolution rule. For all x_15, if x_15 plays a game, then x_15 is an astronaut can be inferred via the universal biconditional elimination rule. For all x_15, if x_15 were an astronaut, then x_15 is playing a game can be inferred via the universal biconditional elimination rule. For all x_15, x_15 is not an astronaut can be inferred via the universal biconditional elimination rule.