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: If Thomas climbs a mountain, then David is not running. Barbara is playing a game if and only if Robert is fast. Barbara is playing a game if and only if Thomas is climbing a mountain. For all x_28, x_28 will go running.
If Barbara plays a game, then Robert is fast can be inferred via the biconditional elimination rule. If Barbara plays a game, then Thomas is climbing a mountain can be inferred via the biconditional elimination rule. If Robert were fast, then Barbara is playing a game can be inferred via the biconditional elimination rule. If Thomas climbs a mountain, then Barbara is playing a game can be inferred via the biconditional elimination rule.