Complementarity of primitive new-mesh markers #
For a primitive new right mesh, this file proves that the deleted simple is a quotient of the ambient left marker exactly when it is not a subobject of the ambient right marker. The proof uses the Hoshino torsion sequence and stable Auslander--Reiten duality directly.
The manuscript's marker-complement statement for a new quotient mesh:
the deleted simple is a quotient of the left marker p_M exactly when it is
not a subobject of the right marker q_N.
Instances For
No map from the left marker can point back to the distinguished primitive projective.
A nonzero map from the left marker to the deleted simple remains nonzero in projective-stable Hom.
The torsion sequence of the right marker q_N.
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Degree-one extensions from the deleted simple into the ambient right marker vanish.
The deleted-simple socle of the torsion-free quotient of q_N is
one-dimensional.
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A nonzero left-marker map supplies a nonzero extension of the deleted simple by the source of the relative mesh.
A nonzero map from the deleted simple into the right marker remains nonzero after passage to the torsion-free quotient.
The two manuscript marker tests are complementary.