In comparison to the previously reported formulation, the influence of the number of included operators (𝑁𝐹), data points (𝑁𝐸), predictor variables (𝑁𝑋), and tree layers (𝑁𝐿) is studied. Figure summarises the obtained results. The scale-up with regard to an increasing number of potential operators was studied first (Figure ). A comparison with the published format is not provided as, for algebraic operators, there is neither a conceptual nor a mathematical difference in the two formulations.