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: William is climbing a mountain if and only if Thomas is running. William is climbing a mountain if and only if it is late. It is not late.
If William climbs a mountain, then Thomas is running can be inferred via the biconditional elimination rule. If William climbs a mountain, then it is late can be inferred via the biconditional elimination rule. If Thomas goes running, then William is climbing a mountain can be inferred via the biconditional elimination rule. If it is late, then William is climbing a mountain can be inferred via the biconditional elimination rule. William is not climbing a mountain can be inferred via the biconditional elimination rule.