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: Mary is curious if and only if Barbara is drinking water. Charles is sad or it is windy. If Charles were sad, then Barbara is drinking water. If it is windy, then Mary is curious.
If Mary were curious, then Barbara is drinking water can be inferred via the biconditional elimination rule. If Barbara drinks water, then Mary is curious can be inferred via the biconditional elimination rule.