DeRhamComputation/heisenberg_covers/heisenberg_group.sage

23 lines
571 B
Python

def heisenberg_mult(v1, v2, p):
i1, j1, k1 = v1
i2, j2, k2 = v2
i3 = (i1 + i2)%p
j3 = (j1 + j2)%p
k3 = (-i2*j1 + k1 + k2)%p
return(i3, j3, k3)
def heisenberg_inv(v1, p):
i1, j1, k1 = v1
i2 = p-i1
j2 = p-j1
k2 = p-k1
k2 = (k2 - i2*j2)%p
return (i2, j2, k2)
def heisenberg_power(v1, n, p):
i1, j1, k1 = v1
if n < 0:
return heisenberg_inv(heisenberg_power((i1, j1, k1), -n, p), p)
if n == 0:
return (0, 0, 0)
return heisenberg_mult((i1, j1, k1), heisenberg_power((i1, j1, k1), n-1, p), p)