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: It is not cold. Thomas is a scientist if and only if William is taking a plane. It is cold if and only if William is taking a plane. If James were a mechanic, then Thomas is a scientist.
If Thomas were a scientist, then William is taking a plane can be inferred via the biconditional elimination rule. If it is cold, then William is taking a plane can be inferred via the biconditional elimination rule. If William takes a plane, then Thomas is a scientist can be inferred via the biconditional elimination rule. If William takes a plane, then it is cold can be inferred via the biconditional elimination rule. William is not taking a plane can be inferred via the biconditional elimination rule.