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: It is late if and only if it is sunny. If it is late, then Mary is a soldier. It is sunny if and only if Mary is a soldier.
If it is late, then it is sunny can be inferred via the biconditional elimination rule. If it is sunny, then Mary is a soldier can be inferred via the biconditional elimination rule. If it is sunny, then it is late can be inferred via the biconditional elimination rule. If Mary were a soldier, then it is sunny can be inferred via the biconditional elimination rule.