t is closed of course if and only if
| X is Hausdorff.)
|
| Let f : X -&gt; Z and g : Y -&gt; Z be two C^p-morphisms, p &gt;= 1.
| We say that they are &quot;transversal&quot; if the morphism:
|
| f x g  :  X x Y  -&gt;  Z x Z
|
| is transversal over the diagonal.  We remark right away
| that the surjectivity of the map in Proposition 2.4 can
| be expressed in two ways.  Given two points x in X and
| y in Y such that f(x) = g(y) = z, the condition:
|
| Im (T_x f) + Im (T_y g)  =  T_z (Z)
|
| is equivalent t