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 it is late, then Elisabeth is drinking water. If Elisabeth drinks water, then it is sunny. It is late or Elisabeth is playing a game. For all x_16, x_16 will play a game if and only if x_16 will drink water.
If Elisabeth were a sailor, then it is late can be inferred via the rewriting rule. For all x_16, if x_16 plays a game, then x_16 is drinking water can be inferred via the universal biconditional elimination rule. For all x_16, if x_16 drinks water, then x_16 is playing a game can be inferred via the universal biconditional elimination rule.