## The binary Golay code [23,12,7]


from PyM import *


n = 23

[_,x] = polynomial_ring(Z_, 'x')

g = factor(x**n-1,Zn(2))[1][0] 

G = cyclic_normalized_matrix(g,n)

show(G)


# The left parity completion $[24,12,7]$ is selfdual

Gb = left_parity_completion(G)

show(Gb*transpose(Gb))