The following article explains the basis for naming the "reaching law" in "sliding Mode Control (SMC)". This article will help those who need to name the "reaching law" in "Sliding Mode Control". https://www.researchgate.net/publication/377205280_The_basis_of_naming_reaching_laws_for_sliding_surface_in_Sliding_Mode_Control_approaches
One of the problems with finding the right name for "law of reaching" in Sliding Mode Control (SMC) is that researchers don't put the right names for "reaching law". A standard was mentioned in this article.