What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_6, x_6 is not a taxi driver. For all x_6, x_6 is happy. For all x_6, x_6 is a mechanic or x_6 is a taxi driver. For all x_6, x_6 is not a mechanic or x_6 is a scientist.
For all x_6, x_6 is a taxi driver or x_6 is a scientist.