numbers discussed in this section. We were unable to find any shorter languages. At least one (noncommutative?) binary operation seem required to start abstract syntax (AST) tree growth (see however Appendix B), and at least one constant to terminate leafs. One of the essential constants $e$ or $\pi$ probably also is required, either explicitly, like in , or hidden in function/operation definition (\[e1\],\[e2\]). But we cannot prove that further reduction to 2 buttons is impossible. We also cannot prove, that above language of length three is unique. Therefore, one cannot estimate Kolmogorov complexity of EL number unambigously. Existence of both smallest and unique language, generating all $\exp-\log$ numbers, would provide natural enumeration of mathematical formulas, similar to Peano arithmetic for natural numbers. Anyway, or are the sets of irreducible operations, for now. Calculator/language can be extended, but under no circumstances any of the buttons defined by or can be removed. Failure to abide by above requirement might result in catastrophic failure of the number recognition software even in the simplest test cases. This is plague of existing implementations, letting unaware end-users to choose base building blocks on their own. This leaves impression of random failures without any obvious reason. Users 