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_6, x_6 will climb a mountain. For all x_6, x_6 is a soldier. For all x_6, if x_6 were a soldier, then x_6 is listening to a song.
For all x_6, x_6 will listen to a song can be inferred via the universal modus ponens rule. For all x_6, x_6 will climb a mountain and x_6 is a soldier can be inferred via the universal conjunction rule. For all x_6, x_6 is a soldier and x_6 will climb a mountain can be inferred via the universal conjunction rule.