                 |
o---------o-------------------o-------------------o-------------------o

The adjectives &quot;differential&quot; or &quot;tangent&quot; are systematically attached to
every construct based on the differential alphabet d!A!, taken by itself.
Strictly speaking, we probably ought to call d!A! the set of &quot;cotangent&quot;
features derived from !A!, but the only time this distinction really
seems to matter is when we need to distinguish the tangent vectors
as maps of type (B^n -&gt; B) -&g