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: Jessica is not a cashier. Thomas is playing a game if and only if Jessica is a cashier. For all x_19, if x_19 were an artist, then x_19 is playing a game.
If Thomas plays a game, then Jessica is a cashier can be inferred via the biconditional elimination rule. If Jessica were a cashier, then Thomas is playing a game can be inferred via the biconditional elimination rule. Thomas is not playing a game can be inferred via the biconditional elimination rule.