What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is cold, then Richard is not a soldier. Richard is a soldier. If Robert makes tea, then it is cold. If it is cold, then Robert is making tea.
It is not cold. If Robert makes tea, then Richard is not a soldier. Robert is making tea if and only if it is cold. It is cold if and only if Robert is making tea.