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 late, then it is overcast. If it is windy, then Karen is climbing a mountain. If it is windy, then it is late. If Karen climbs a mountain, then it is windy.
If it is windy, then it is overcast can be inferred via the transitivity rule. If Karen climbs a mountain, then it is late can be inferred via the transitivity rule. It is windy if and only if Karen is climbing a mountain can be inferred via the biconditional introduction rule. Karen is climbing a mountain if and only if it is windy can be inferred via the biconditional introduction rule.