What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_7, x_7 will make tea or x_7 will play squash. For all x_7, if x_7 plays squash, then x_7 is a server. For all x_7, x_7 will not write a letter. For all x_7, x_7 will write a letter if and only if x_7 will make tea.
For all x_7, if x_7 writes a letter, then x_7 is making tea. For all x_7, if x_7 makes tea, then x_7 is writing a letter. For all x_7, x_7 will not make tea.