Then, we proceed by considering 𝑇 1 varying in the calculation of 𝐾 and ℎ $ and comparing the SAS results with well-known fixed-step numerical methods: explicit Euler, Heun, Ralston, and Runge-Kutta of 3 rd , 4 th and 5 th order (all these methods were implemented by us). All calculations are performed on a computer with an Intel ® Core™ i5-10400F CPU running at 2.9 GHz (6 cores, 12 threads), 64 GB RAM, and Windows 11 Pro 64-bit.