t; \   / f'
|                         v /
|                          o
|                         B^k
|
| This says that f(x)  =  f'(c(x))  =  f'(x&lt;1&gt;(x), ..., x&lt;k&gt;(x)), where
|
| c(x)  =  the "code" of x  =  the bit-list &lt;x&lt;1&gt;(x), ..., x&lt;n&gt;(x)&gt; in B^k
|
| is the binary coding of the element x in X, and where
|
| f' is the "derived mapping" from codes to B.
|
| Given this sort of set-up, we can proceed to work with
| derived propositions f' : B^k -&gt; B, using truth tables
| or