What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one x_15 for which x_15 is not curious. For all x_15, x_15 will work or x_15 is happy. For all x_15, x_15 will write a letter. For all x_15, x_15 is curious if and only if x_15 will work.
For all x_15, if x_15 were curious, then x_15 is working. For all x_15, if x_15 works, then x_15 is curious. There is at least one x_15 for which x_15 will not work.