Bases: sage.modular.arithgroup.congroup_generic.CongruenceSubgroup
The principal congruence subgroup .
Return the index of self in the full modular group. This is given by
Return the number of cusps of this subgroup .
EXAMPLES:
sage: [Gamma(n).ncusps() for n in [1..19]]
[1, 3, 4, 6, 12, 12, 24, 24, 36, 36, 60, 48, 84, 72, 96, 96, 144, 108, 180]
sage: Gamma(30030).ncusps()
278691840
sage: Gamma(2^30).ncusps()
432345564227567616
Return the congruence subgroup .
EXAMPLES:
sage: Gamma(5) # indirect doctest
Congruence Subgroup Gamma(5)
sage: G = Gamma(23)
sage: G is Gamma(23)
True
sage: G == loads(dumps(G))
True
sage: G is loads(dumps(G))
True
Return True if x is a congruence subgroup of type Gamma.
EXAMPLES:
sage: from sage.modular.arithgroup.all import is_Gamma
sage: is_Gamma(Gamma0(13))
False
sage: is_Gamma(Gamma(4))
True