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GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it

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<Chapter><Heading> Some functions for accessing basic data</Heading>

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<Table Align="|l|" >

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<Row>

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<Item>

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<Index>BoundaryMap</Index>

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<C>BoundaryMap(C)</C>

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<P/>

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Inputs a resolution, chain complex or cochain complex <M>C</M>

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and returns the function <M>C!.boundary</M>.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> BoundaryMatrix</Index>

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<C>BoundaryMatrix(C,n)</C>

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<P/>

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Inputs a chain or cochain complex <M>C</M> and integer <M>n</M>&tgt;<M>0</M>. It returns the <M>n</M>-th boundary map of <M>C</M> as a matrix.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> Dimension</Index> 

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<C>Dimension(C)

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</C>

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<Br/>

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<C>Dimension(M) </C>

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<P/>

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Inputs a resolution, chain complex or cochain complex <M>C</M>

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and returns the function <M>C!.dimension</M> .

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<P/>

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Alternatively, inputs an <M>FpG</M>-module <M>M</M>

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and returns its dimension as a vector space over the field of <M>p</M>

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elements.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> EvaluateProperty</Index>

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<C>EvaluateProperty(X,"name") </C>

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<P/>

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Inputs a component object <M>X</M> 

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(such as a <M>ZG</M>-resolution or chain map) and a string 

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"name" (such as "characteristic" or "type"). It searches <M>X.property</M> for the  pair ["name",value] and returns value. If <M>X.property</M>

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does not exist, or if ["name",value] does not exist, it returns fail.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> GroupOfResolution</Index>

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<C>GroupOfResolution(R)</C>

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<P/>

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Inputs a <M>ZG</M>-resolution <M>R</M> and returns the group <M>G</M>.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> Length</Index>

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<C>Length(R)</C>

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<P/>

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Inputs a resolution <M>R</M> and returns its length 

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(i.e. the number of terms of <M>R</M> that HAP has computed). 

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> Map</Index>

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<C>Map(f)</C>

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<P/>

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Inputs a chain map, or cochain map or equivariant chain map <M>f</M>

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and returns the mapping function (as opposed to the 

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target or the source of <M>f</M>) .

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> Source</Index>

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<C>Source(f)</C>

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<P/>

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Inputs a chain map, or cochain map, or equivariant chain map, or 

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<M>FpG</M>-module homomorphism <M>f</M> and returns it source.

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</Item>

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</Row>

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<Row>

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<Item>

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<Index> Target</Index>

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<C>Target(f)</C>

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<P/>

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Inputs a chain map, or cochain map, or equivariant chain map, or 

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<M>FpG</M>-module homomorphism <M>f</M> and returns its target.

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</Item>

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</Row>

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</Table>

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</Chapter>

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