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             |                            Welcome to tnorm!                         
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             |         To get started, enter the name of a manifold in the          
             +-------- Manifold field, and click Load. Any string accepted          
                       by SnapPy is accepted here, e.g., '4_1', 'DT:[(6,8,2,4)]',  
                       'L5a1' (without quotes). To open a file containing a 
                       triangulation (with extention .tri), type 'file' and 
                       click Load.                                       
                                                                                                       
                       After loading a manifold, click the 'norm ball' or           
                       'dual norm ball' tabs to view more detailed information      
                       about each, or click on the 'qton surfaces' tab to view 
                       information about all quad transversely oriented (vertex) 
                       normal surfaces (not just vertices of the norm ball). 
                       Buttons at left give additional information about the 
                       norm ball.

                       In the case where the Thurston norm is a semi-norm (and 
                       not a norm), e.g., when the manifold is not hyperbolic,
                       things may go wrong. You should not trust the results of 
                       such computations, though they might be correct for some
                       manifolds. When tnorm IS able to compute the norm ball, it
                       is a non-compact polyhedron, so we can only graph its
                       projection to the subspace in which it is a norm. We also
                       give the option in this case of viewing the convex hull of
                       the image in H2 of normal surfaces having negative Euler
                       characteristic (this is a finite polyhedron).


