A System with a Recursion Operator but One Higher Local Symmetry of the Form $u_t=u_{xxx}+f(t,x,u,u_x,u

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/94522We construct a recursion operator for the system $(u_t,v_t)=(u_4+v^2,1/5 v_4)$, for which only one local symmetry is known and we show that the action of the recursion operator on $(u_t,v_t)$ is a local function.7 pages, no figuresExactly Solvable and Integrable SystemsA System with a Recursion Operator but One Higher Local Symmetry of the Form $u_t=u_{xxx}+f(t,x,u,u_x,u_{xx})$text