In the two papers [4] and [5], Košir and Sethuraman proved that Z 2,2 , the first order jet scheme over the variety Z m,n 2 of m × n matrices of rank at most 1, has two components: a principal component Z0 which is the closure of the jets over the nonsingular points of Z 2 , and a second component supported over the origin that is just affine space. They… (More)