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 it is sunny, then Patricia is happy. It is sunny if and only if it is cloudy. It is cloudy if and only if Patricia is happy.
If it is sunny, then it is cloudy can be inferred via the biconditional elimination rule. If it is cloudy, then Patricia is happy can be inferred via the biconditional elimination rule. If it is cloudy, then it is sunny can be inferred via the biconditional elimination rule. If Patricia were happy, then it is cloudy can be inferred via the biconditional elimination rule.