 The interaction between infinite reduction sequences and nfs deserves a more careful inspection though. The terms \(\textsf{WWW}\), \(\textsf{Y} (\textsf{CKI})\) and \(\textsf{WI}(\textsf{WI})\) have only infinite reduction sequences. However, the existence of an infinite reduction sequence for a term does not imply that the term has no normal form (when the combinatory base is complete or contains a cancellator). \(\textsf{Y} (\textsf{KI})\) reduces to \(\textsf{KI}(\textsf{Y}(\textsf{KI}))\), \(\textsf{KI}(\textsf{KI}(\textsf{Y}(\textsf{KI})))\), \(\textsf{KI} (\textsf{KI}(\textsf{KI}(\textsf{Y}(\textsf{KI})))),\ldots\) as well as to \(\textsf{I}\).