What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Joseph is taking a plane. For all x_6, if x_6 writes a letter, then x_6 is drinking water. For all x_6, if x_6 takes a plane, then x_6 is writing a letter.
There is at least one x for which x will take a plane. For all x_6, if x_6 takes a plane, then x_6 is drinking water.