Let Q be a bounded open domain in R^n with smooth boundaryаΩ.Let X=(X1,X2…,Xm)be a system of general Grushin type vector fields defined onΩand the boundary
In this paper,a weak type(1,1)estimate is established for the higher order commutator introduced by Christ and Joume which is defined byT[a1,…,a1]f(x)=p.v∫R^d