  The Nielsen-Ninomiya no-go theorem asserts that chiral Weyl~(``neutrino'')
fields cannot exist on lattices. However, the actual mathematical arguments
advanced in the theorem fail to make that case. The theorem leaves the problem
of lattice neutrinos completely open; it identifies no obstacle which would
prevent us from discretizing chiral theories.
  (INFORMAL ABSTRACT: Have you too, like every second person in the field, been
citing the Nielsen-Ninomiya theorem but have not read or analyzed it? Then,
this paper will wake you up. Reading it is a prerequisite to doing any good
work in chiral lattice physics.)
