Kernel of a linear application : kernel nullspace ker

ker (or kernel or nullspace) takes as argument the matrix of an linear application f with respect to the canonical basis.
ker (or kernel or nullspace) returns a list of vectors that is a basis of the kernel of f.
Input :

ker([[1,1,2],[2,1,3],[3,1,4]])

Output :

[[1,1,-1]]

The kernel is generated by the vector [1,1,-1].