<A NAME=KERNEL>
<TITLE>KERNEL</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>
<B>KERNEL</B> _ _ _ _ _ _ _ _ _ _ _ _ <B>type</B><P>
<P>
A <em>kernel</em> is a form that cannot be modified further by the REDUCE
canonical simplifier. Scalar variables are always kernels. The
other important class of kernels are operators with their arguments.
Some examples should help clarify this concept:
<P>
<P>
<P><PRE><TT>
Expression Kernel?
x Yes
varname Yes
cos(a) Yes
log(sin(x**2)) Yes
a*b No
(x+y)**4 No
matrix-identifier No
</TT></PRE><P>Many REDUCE operators expect kernels among their arguments. Error
messages
result from attempts to use non-kernel expressions for these arguments.
<P>
<P>