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: Charles is playing a game if and only if Jessica is a sailor. Charles is playing a game if and only if Jessica is a sailor.
If Charles plays a game, then Jessica is a sailor can be inferred via the biconditional elimination rule. If Charles plays a game, then Jessica is a sailor can be inferred via the biconditional elimination rule. If Jessica were a sailor, then Charles is playing a game can be inferred via the biconditional elimination rule. If Jessica were a sailor, then Charles is playing a game can be inferred via the biconditional elimination rule.