addgphom.gd

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#W  addgphom.gd                 GAP library                      Scott Murray
#W                                                           Alexander Hulpke
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#Y  (C) 2000 School Math and Comp. Sci., University of St Andrews, Scotland
#Y  Copyright (C) 2002 The GAP Group
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##  This file contains declarations for mappings between groups and additive
##  groups.
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#F  GroupToAdditiveGroupHomomorphismByFunction( <S>, <R>, <fun> )
#F  GroupToAdditiveGroupHomomorphismByFunction( <S>, <R>, <fun>, <invfun> )
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##  `GroupToAdditiveGroupHomomorphismByFunction' returns a
##  group-to-additive-group homomorphism <hom> with
##  source <S> and range <R>, such that each element <s> of <S> is mapped to
##  the element `<fun>( <s> )', where <fun> is a {\GAP} function.
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##  If the argument <invfun> is bound then <hom> is a bijection between <S>
##  and <R>, and the preimage of each element <r> of <R> is given by
##  `<invfun>( <r> )', where <invfun> is a {\GAP}  function.
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##  No test is performed on whether the functions actually give an
##  homomorphism between both groups because this would require testing the
##  full multiplication table.
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##  `GroupToAdditiveGroupHomomorphismByFunction' creates a mapping which
##  `IsSPGeneralMapping'.
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DeclareGlobalFunction("GroupToAdditiveGroupHomomorphismByFunction");

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#E