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: Joseph is climbing a mountain. Joseph is climbing a mountain if and only if it is sunny. For all x, x is a musician.
If Joseph climbs a mountain, then it is sunny can be inferred via the biconditional elimination rule. If it is sunny, then Joseph is climbing a mountain can be inferred via the biconditional elimination rule.