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math.AG2002
Fano's inequality is false for a simple Cremona transformation of five-dimensional projective space
Marat Gizatullin
A Cremona transformation of five-dimensional projective space is constructed. The degree of the transformation is 7. The inequalities of Fano are not fulfilled for this transformat…
math.AG2002
Fano's inequality is also false for three-dimensional quadric
Marat Gizatullin
A birational transformation of three-dimensional quadric is constructed. The inequalities of fano are not fulfilled for this transformation.
math.AG2002
Fano's inequality is a mistake
Marat Gizatullin
An example of a Cremona transformation of the tree-dimensional projective space is presented. For the transformation, the inequalities of Fano are not valid.