Cauchy matrix scheme for semidiscrete lattice Korteweg–de Vries-type equations

Based on a determining equation set and master function, we consider a Cauchy matrix scheme for three semidiscrete lattice Korteweg–de Vries-type equations. The Lax integrability of these equations is discussed. Various types of solutions, including soliton solutions, Jordan-block solutions, and mixed solutions are derived by solving the determining equation set. Specifically, we find $1$-soliton, $2$-soliton, and the simplest Jordan-block solutions for the semidiscrete lattice potential Korteweg–de Vries equation.