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 Patricia were a poet, then it is sunny. If David works, then Patricia is a poet. It is sunny or David is working. If it is sunny, then Patricia is a poet.
If David works, then it is sunny can be inferred via the transitivity rule. Patricia is a poet can be inferred via the disjunction elimination rule. Patricia is a poet if and only if it is sunny can be inferred via the biconditional introduction rule. It is sunny if and only if Patricia is a poet can be inferred via the biconditional introduction rule.