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 sunny, then Elisabeth is playing a game. It is sunny if and only if Charles is an artist. Elisabeth is playing a game if and only if Charles is an artist.
If it is sunny, then Charles is an artist can be inferred via the biconditional elimination rule. If Elisabeth plays a game, then Charles is an artist can be inferred via the biconditional elimination rule. If Charles were an artist, then it is sunny can be inferred via the biconditional elimination rule. If Charles were an artist, then Elisabeth is playing a game can be inferred via the biconditional elimination rule.