It turns out that Guido does not like or encourage the use of the term
"disciplines" for the __*__() methods, so they should be referred to as
"methods" or "special methods", as appropriate in context.
diff --git a/Doc/lib/liboperator.tex b/Doc/lib/liboperator.tex
index 69ae23b..cf42133 100644
--- a/Doc/lib/liboperator.tex
+++ b/Doc/lib/liboperator.tex
@@ -89,8 +89,8 @@
 \begin{funcdesc}{not_}{o}
 \funcline{__not__}{o}
 Return the outcome of \keyword{not} \var{o}.  (Note that there is no
-\method{__not__()} discipline for object instances; only the
-interpreter core defines this operation.)
+\method{__not__()} method for object instances; only the interpreter
+core defines this operation.)
 \end{funcdesc}
 
 \begin{funcdesc}{truth}{o}