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: If John drinks water, then Patricia is a mechanic. Robert is a carpenter if and only if Jennifer is listening to a song. John is drinking water or Jennifer is listening to a song. If Robert were a carpenter, then Patricia is a mechanic.
If Robert were a carpenter, then Jennifer is listening to a song can be inferred via the biconditional elimination rule. If Jennifer listens to a song, then Robert is a carpenter can be inferred via the biconditional elimination rule.