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: For all y, if y makes tea, then y is a scientist. Jessica is a scientist or John is not playing a game. For all y, if y were a scientist, then y is making tea. Jessica is making tea or John is playing a game.
If John plays a game, then Jessica is a scientist can be inferred via the rewriting rule. For all y, y will make tea if and only if y is a scientist can be inferred via the universal biconditional introduction rule. For all y, y is a scientist if and only if y will make tea can be inferred via the universal biconditional introduction rule.