1proc(x,y) [x|-> ] { 2 x->tl = y; 3} [x|-> tl:y] 4 5main(x,z;)[emp] { 6 x = new(); z= new(); x->tl=3; z->tl=3; 7 proc(x,4) || proc(z,5); 8} [x|->tl:4 * z|-> tl:5]