What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Jessica is not fast. Richard is playing tennis or Robert is a poet. Richard is playing tennis if and only if Susan is happy. Susan is happy if and only if Jessica is fast.
If Richard plays tennis, then Susan is happy. If Susan were happy, then Jessica is fast. If Susan were happy, then Richard is playing tennis. If Jessica were fast, then Susan is happy. Susan is not happy.