Table:
Six homomorphisms from cmm
| type |
P(k) = -1 |
wallpaper type of kernel group, with remarks |
cmm
![[Image]](../../../buttons/image.gif) |
none |
cmm, same as the extended group |
cmm'
![[Image]](../../../buttons/image.gif) |
R |
cm = {t1, Mx} |
| |
R and Mx |
same as above,
i(M) = R Mx |
cm'm'
 |
Mx |
p2 = {d, d', R} |
p'cmm
![[Image]](../../../buttons/image.gif) |
d |
pmm = {t1, t2, Mx, R};
cell doubled |
p'cmg
![[Image]](../../../buttons/image.gif) |
d and R |
pmg = {t1, t2, Mx, d R};
cell doubled |
| |
d, R and Mx |
same as above,
i(M) = R Mx |
p'cgg
 |
d and Mx |
pgg = {d Mx (= L), R};
cell doubled |