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Conditioned Presentations

Conditioned Presentations

Magma will compute an internal pc-presentation which will be used for internal computation, but the user's presentation will be used for all input and output. The recommended way to access the conditioned internal presentation is via the intrinsic ConditionedGroup.

Subsections

Structure Operations

ConditionedGroup(G) : GrpPC -> GrpPC
The internally used, conditioned presentation of the pc-group G.
IsConditioned(G) : GrpPC -> BoolElt
True if G has a conditioned presentation, false otherwise.

Element Operations

LeadingTerm(x) : GrpPCElt -> GrpPCElt
Given an element x of a pc-group G with n pc-generators and a conditioned presentation, where x is of the form a_1^(alpha_1) ... a_n^(alpha_n), return a_i^(alpha_i) for the smallest i such that alpha_i > 0. If x is the identity of G, then the identity is returned.
LeadingGenerator(x) : GrpPCElt -> GrpPCElt
Given an element x of a pc-group G with n pc-generators and a conditioned presentation, where x is of the form a_1^(alpha_1) ... a_n^(alpha_n), return a_i for the smallest i such that alpha_i > 0. If x is the identity of G, then the identity is returned.
LeadingExponent(x) : GrpPCElt -> RngIntElt
Given an element x of a pc-group G with n pc-generators and a conditioned presentation, where x is of the form a_1^(alpha_1) ... a_n^(alpha_n), return alpha_i for the smallest i such that alpha_i > 0. If x is the identity of G, then 0 is returned.
Depth(x) : GrpPCElt -> RngIntElt
Given an element x of a pc-group G with n pc-generators and a conditioned presentation, where x is of the form a_1^(alpha_1) ... a_n^(alpha_n), return the smallest i such that alpha_i > 0. If x is the identity of G, then 0 is returned.
PCClass(x) : GrpPCElt -> RngIntElt
WeightClass(x) : GrpPCElt -> RngIntElt
The weight class of the element x. The WeightClass of an arbitrary element of a pc-group G is defined to be k if x in G_(delta_(k - 1)) and x notin G_(delta_(k)). If x is the identity of G, then WeightClass returns n + 1.
PCPrimes(G) : GrpPC -> [RngIntElt]
A sequence [p_1, ..., p_n] containing the primes associated with the pc-generators of G. The i-th term of the sequence contains the prime associated with generator a_i of G for i = 1, ..., n.
ElementToSequence(x) : GrpPCElt -> [RngIntElt]
Eltseq(x) : GrpPCElt -> [RngIntElt]
Given an element x of a pc-group G, where x = a_1^(alpha_1) ... a_n^(alpha_n), 0 <= alpha_i < p_i for i = 1, ..., n, return the sequence Q of n integers defined by Q[i] = (alpha_i), for i = 1, ..., n.
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