Table:
Six homomorphisms from pmg
| type |
P(k) = -1 |
wallpaper type of kernel group, with remarks |
pmg
![[Image]](../../../buttons/image.gif) |
none |
pmg, same as the extended group |
p'bmg
![[Image]](../../../buttons/image.gif) |
t1 |
pmg = {t12, Lv, A}
|
| |
t1 and Lv |
same as above,
i(Lv) = Lv t1 |
pmg'
![[Image]](../../../buttons/image.gif) |
Lv |
pm = {t1, Lv2, A};
R negative |
pm'g
![[Image]](../../../buttons/image.gif) |
A |
pg = {t1, Lv};
R negative |
p'bgg
 |
t1 and A |
pgg = {t12, Lv, t1 A};
doubled cell |
| |
t1, Lv and A |
same as above,
i(Lv) = Lv t1 |
pm'g'
![[Image]](../../../buttons/image.gif) |
Lv and A |
p2 = {t1, Lv2, Lv A};
R positive |