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2 The Commuting Graph
 2.1 CommGraph Main Functions

2 The Commuting Graph

2.1 CommGraph Main Functions

2.1-1 CommGraph
‣ CommGraph( group )( function )

This function receives a group as an input then utilizes the Grape package to implement a graph (V,E) applying the following rule:

The vertices of this graph are the elements of the inputted group G and two vertices are connected if the elements commute

2.1-2 DeepCommGraph
‣ DeepCommGraph( group )( function )

This function receives a group as an input then utilizes the Grape package to implement a graph (V,E) applying the following rule:

Two elements of G are joined in the deep commuting graph if and only if their preimages in every central extension of G (that is, every group H with a central subgroup Z such that H/Z \cong G) commute.

2.1-3 CommDegree
‣ CommDegree( group )( function )

The commutativity degree of a group is defined as the probability that two elements of the group commutes.

The CommDegree function receives a group as an input then outputs a number \text{CommDegree}(G) \in (\frac{5}{8}, 1) that represents this probability. If the group is abelian, then the commutative degree is 1. Otherwise it is always less than \frac{5}{8} as a consequence of the \frac{5}{8} lower bound theorem.

2.1-4 MaxAbelianSubgroup
‣ MaxAbelianSubgroup( group )( function )

This function receives a group as an input then utilizes the Grape package function MaximumClique(graph) to return the group generated by a maximum clique of the group's commutative graph.

2.1-5 CommDegreeGroupFind
‣ CommDegreeGroupFind( group )( function )

This function receives an integer number n and then outputs a group G with commutativity degree frac1n.

2.1-6 PrimeCommDegreeGroupFind
‣ PrimeCommDegreeGroupFind( prime )( function )

The PrimeCommDegreeGroupFind function receives a prime number p and returns a group G with commutativity degree frac1p, the CommDegreeGroupFind function uses this function taking the prime factorization of the number n and taking the direct product of the groups with commmutativity degree equal to frac1p_i.

2.1-7 NilpotentCommDegreeGroupFind
‣ NilpotentCommDegreeGroupFind( number )( function )

Similar to the PrimeCommDegreeGroupFind, but returning a nilpotent group with commutativity degree less than frac1n given an integer number n.

2.1-8 NilpotentPrimeCommDegreeGroupFind
‣ NilpotentPrimeCommDegreeGroupFind( prime )( function )

Similar to the PrimeCommDegreeGroupFind, but returning a nilpotent group with commutativity degree less than frac1p given a prime number p.

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