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: Robert is a musician if and only if it is raining. Charles is not a poet. Charles is a poet if and only if Robert is a musician.
If Robert were a musician, then it is raining can be inferred via the biconditional elimination rule. If Charles were a poet, then Robert is a musician can be inferred via the biconditional elimination rule. If it rains, then Robert is a musician can be inferred via the biconditional elimination rule. If Robert were a musician, then Charles is a poet can be inferred via the biconditional elimination rule. Robert is not a musician can be inferred via the biconditional elimination rule.