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 Patricia were a carpenter, then Sarah is playing squash. For all x_10, if x_10 climbs a mountain, then x_10 is a poet. If Sarah plays squash, then Charles is climbing a mountain.
If Patricia were a carpenter, then Charles is climbing a mountain can be inferred via the transitivity rule.