hi,<br><br>What is the different between &#39;in beta normal form&#39; and &#39;has
beta normal form&#39; ? Does the former means the current form of the term
is already in normal form but the latter means that it is not a normal
form yet and can be reduced to be normal form? Like  \x.x is in NF and
(\x.x) (\x.x) has NF?<br>
<br>If above is true, I am confused why we have to distinguish the
terms which have NF and be in NF? isn&#39;t the terms have NF will
eventually become in NF? or there are some way to avoid them becoming
in NF?<br><br>Thanks<br><br>Alg<br>