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 x_12, x_12 is a poet if and only if x_12 will cook. For all x_12, x_12 is an artist. There is at least one x_12 for which x_12 is a poet.
There is at least one x_12 for which x_12 is a poet and x_12 is an artist can be inferred via the existential conjunction rule. There is at least one x_12 for which x_12 is an artist and x_12 is a poet can be inferred via the existential conjunction rule. For all x_12, if x_12 were a poet, then x_12 is cooking can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 cooks, then x_12 is a poet can be inferred via the universal biconditional elimination rule.