# Checker for O'N
# Check orders of a, b and ab
chor 1 2
chor 2 4
mu 1 2 3
chor 3 11
# We construct an element of order 5 which commutes with
# b, thus proving that b is in 4A (as |C(4B)|=256).
mu 2 2 4
mu 3 3 5
cj 4 5 6
mu 4 6 7
pwr 5 7 8
mu 5 8 9 # abab(b^2(b^2)^(abab))^5; it commutes with b
chor 9 5
com 2 9 10
chor 10 1