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: Jennifer is not writing a letter. It is windy and James is happy. Jennifer is writing a letter if and only if Patricia is a server.
It is windy can be inferred via the simplification rule. James is happy can be inferred via the simplification rule. If Jennifer writes a letter, then Patricia is a server can be inferred via the biconditional elimination rule. If Patricia were a server, then Jennifer is writing a letter can be inferred via the biconditional elimination rule. Patricia is not a server can be inferred via the biconditional elimination rule.