On the Ries inequality and the basicity of systems of root vector functions of $2m$th order Dirac-type operator with summable coefficient

We consider a Dirac-type operator of $2m$th order on a finite interval $G=(a,b).$ It is assumed that its coefficient is a complex-valued matrix function summable on $G=(a,b)$. A Riesz property criterion is established for a system of root vector functions, and a theorem on the equivalent basis property in $L_{p}^{2m} (G), \ 1<p<\infty $ is proved.