Consider the following premises. If Elisabeth goes running, then Patricia is reading a book. Patricia is reading a book if and only if Elisabeth is running. If it is late, then Patricia is reading a book. If Patricia reads a book, then it is late. It is not late. Can we infer the following from them? Elisabeth is not running.
 From the fact that if Patricia reads a book, then it is late, and that if it is late, then Patricia is reading a book we can infer that Patricia is reading a book if and only if it is late. From the fact that Patricia is reading a book if and only if Elisabeth is running we can infer that if Patricia reads a book, then Elisabeth is running. From the fact that if Patricia reads a book, then Elisabeth is running, and that if Elisabeth goes running, then Patricia is reading a book we can infer that Patricia is reading a book if and only if Elisabeth is running. From the fact that Patricia is reading a book if and only if it is late, and that it is not late we can infer that Patricia is not reading a book. Finally, from the fact that Patricia is reading a book if and only if Elisabeth is running, and that Patricia is not reading a book we can infer that Elisabeth is not running. Therefore, the answer is yes.