Dim
type t = int
and change = {
dim : int array;
intdim : int;
realdim : int;
}
and change2 = {
add : change option;
remove : change option;
and perm = int array
and dimension = {
intd : int;
reald : int;
val change_add_invert : change -> unit
val perm_compose : perm -> perm -> perm
val perm_invert : perm -> perm