Small equation images

You can obtain all the elementary functions from just the function

$\operatorname{fn}(x,y) = \exp(x) - \log(y)$

and the constant 1. The following equations show how to bootstrap addition and subtraction.

$\begin{align*} \exp(z) &\mapsto \operatorname{fn}(z,1) \\ \log(z) &\mapsto \operatorname{fn}(1,\exp(\operatorname{fn}(1,z))) \end{align*}$

See the paper for more details.