Modern and planned high-energy physics experiments promise to provide a lot of high-precision experimental data. The high precision is especially important in the context of searches of deviations from Standard Model predictions – the New Physics. Consequently, the theoretical predictions should also have high precision, which in practice means going beyond NLO (1 loop) approximation. Fortunately, the multiloop calculational methods have evolved enough to provide this precision (with some reservations). However, even at NNLO level, the final results are already cumbersome, which may complicate their practical use in experimental data processing. The speaker will address the question of simplification of the results of multiloop calculations. As a rule, these results are expressed in terms of classical, harmonic, or Goncharov’s polylogarithms, which all represent the examples of iterated path integrals (or Chen’s iterated integrals, not to be confused with functional integrals). The researcher will talk about two aspects of this simplification. There will be an explanation of how the expression involving classical polylogarithms can be simplified using functional identities between polylogarithms. Then some issues related to the simplification of iterated path integrals in multivariate case will be discussed.