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: For all x_13, if x_13 reads a book, then x_13 is climbing a mountain. For all x_13, if x_13 were a writer, then x_13 is reading a book. Patricia is climbing a mountain if and only if Patricia is a writer. Patricia is not climbing a mountain.
If Patricia climbs a mountain, then Patricia is a writer can be inferred via the biconditional elimination rule. If Patricia were a writer, then Patricia is climbing a mountain can be inferred via the biconditional elimination rule. For all x_13, if x_13 were a writer, then x_13 is climbing a mountain can be inferred via the universal transitivity rule.