4 Ring Maps
  
  
  4.1 Ring Maps: Attributes
  
  4.1-1 KernelSubobject
  
  KernelSubobject( phi )  method
  Returns:  a homalg submodule
  
  The kernel ideal of the ring map phi.
  
  
  4.2 Ring Maps: Operations and Functions
  
  4.2-1 SegreMap
  
  SegreMap( R, s )  method
  Returns:  a homalg ring map
  
  The  ring  map corresponding to the Segre embedding of MultiProj(R) into the
  projective space according to P(W_1)× P(W_2) -> P(W_1⊗ W_2).
  
  4.2-2 PlueckerMap
  
  PlueckerMap( l, n, A, s )  method
  Returns:  a homalg ring map
  
  The  ring  map  corresponding  to  the Plücker embedding of the Grassmannian
  G_l(P^n(A))=G_l(P(W)) into the projective space P(⋀^l W), where W=V^* is the
  A-dual of the free module V=A^n+1 of rank n+1.
  
  4.2-3 VeroneseMap
  
  VeroneseMap( n, d, A, s )  method
  Returns:  a homalg ring map
  
  The ring map corresponding to the Veronese embedding of the projective space
  P^n(A)=P(W) into the projective space P(S^d W), where W=V^* is the A-dual of
  the free module V=A^n+1 of rank n+1.