Algorithm of integrating stiff problems using the explicit and implicit methods

An $L$-stable $(3,2)$-method order 3 and an explicit three-stage Runge–Kutta scheme order 1 are constructed. An integration algorithm of variable order and step is constructed that is based on of the two schemes The most effective numerical scheme is chosen for each step by means of stability control. The results are given that confirm the effectiveness of the algorithm.