<Verb>Mod2CohomologyRingPresentation(G):: Group --> PresentedGradedAlgebra</Verb>
<Verb>Mod2CohomologyRingPresentation(G,n):: Group --> PresentedGradedAlgebra</Verb>  
<Verb>Mod2CohomologyRingPresentation(A):: Group --> PresentedGradedAlgebra</Verb>  
<Verb>Mod2CohomologyRingPresentation(R):: Group --> PresentedGradedAlgebra</Verb><P/>


When applied to a finite <M>2</M>-group <M>G</M> this function returns a 
presentation for the mod-<M>2</M> cohomology ring <M>H^\ast(G,\mathbb F)</M>.
 The Lyndon-Hochschild-Serre spectral sequence is used to prove that the 
presentation is complete.

When the function is applied to a <M>2</M>-group G and positive integer <M>n</M>
 the function first constructs <M>n+1</M> terms of a free 
<M>\mathbb FG</M>-resolution <M>R</M>, then constructs the finite-dimensional 
graded algebra <M>A=H^{(\ast \le n)}(G,\mathbb F)</M>, and finally uses <M>A</M>
 to approximate a presentation for <M>H^*(G,\mathbb F)</M>. For "sufficiently large" <M>n</M> the approximation will be a correct presentation for 
<M>H^\ast(G,\mathbb F)</M>.

Alternatively, the function can be applied directly to either the resolution <M>R</M> or graded algebra <M>A</M>.

This function was written by Paul Smith. It uses the Singular commutative algebra package to handle the Lyndon-Hochschild-Serre spectral sequence.

