t;|a_1, ..., a_n,  da_1, ..., da_n|&gt;,

thus giving EA the type B^n x D^n.

Finally, the tangent universe EA% = [E!A!] is constituted from the totality
of points and maps, or interpretations and propositions, which are based on
the extended set of features E!A!:

   EA%  =  [E!A!]  =  [a_1, ..., a_n,  da_1, ..., da_n],

thus giving the tangent universe E!A! the type
(B^n x D^n +-&gt; B) = (B^n x D^n, (B^n x D^n -&gt; B).

A proposition in the tangent universe [E!A!] is
called a &quot;differential proposit