-heavily used, simplification occurs frequently. Therefore @code{.normal()},
-which provides some basic form of simplification, has become a method of
-class @code{ex}, just like @code{.expand()}.
-It converts a rational function into an equivalent rational function
-where numererator and denominator are coprime. This means, it finds
-the GCD of numerator and denominator and cancels it. If it encounters
-some object which does not belong to the domain of rationals (a
-function for instance), that object is replaced by a temporary symbol.
-This means that both expressions @code{t1} and
-@code{t2} are indeed simplified in this little program:
+heavily used, simplification is called for frequently. Therefore
+@code{.normal()}, which provides some basic form of simplification, has
+become a method of class @code{ex}, just like @code{.expand()}. It
+converts a rational function into an equivalent rational function where
+numerator and denominator are coprime. This means, it finds the GCD of
+numerator and denominator and cancels it. If it encounters some object
+which does not belong to the domain of rationals (a function for
+instance), that object is replaced by a temporary symbol. This means
+that both expressions @code{t1} and @code{t2} are indeed simplified in
+this little program: