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 cold, then Sarah is a poet. It is cold or Sarah is playing squash. For all z, if z plays squash, then z is a poet. Robert is an office clerk or Sarah is not a poet.
If Sarah were a mechanic, then it is cold can be inferred via the rewriting rule. If Sarah were a poet, then Robert is an office clerk can be inferred via the rewriting rule.