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 overcast, then Thomas is a mechanic. Thomas is a mechanic if and only if it is snowing. Robert is making tea if and only if it is overcast. It is not snowing.
If Thomas were a mechanic, then it is snowing can be inferred via the biconditional elimination rule. If Robert makes tea, then it is overcast can be inferred via the biconditional elimination rule. If it snows, then Thomas is a mechanic can be inferred via the biconditional elimination rule. If it is overcast, then Robert is making tea can be inferred via the biconditional elimination rule. Thomas is not a mechanic can be inferred via the biconditional elimination rule.