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_13 for which x_13 will not write a letter. For all x_13, if x_13 makes tea, then x_13 is a poet. For all x_13, x_13 will make tea if and only if x_13 will write a letter. For all x_13, if x_13 were a poet, then x_13 is making tea.
For all x_13, x_13 will make tea if and only if x_13 is a poet. For all x_13, x_13 is a poet if and only if x_13 will make tea. For all x_13, if x_13 makes tea, then x_13 is writing a letter. For all x_13, if x_13 writes a letter, then x_13 is making tea. There is at least one x_13 for which x_13 will not make tea.