What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_1, x_1 is not a scientist. Thomas is writing a letter if and only if it is windy. For all x_1, x_1 will write a letter if and only if x_1 is a scientist.
If Thomas writes a letter, then it is windy. If it is windy, then Thomas is writing a letter. For all x_1, if x_1 writes a letter, then x_1 is a scientist. For all x_1, if x_1 were a scientist, then x_1 is writing a letter. For all x_1, x_1 will not write a letter.