Witt’s cancellation theorem seen as a cancellation

Cancellation theorem

A Cancellation Theorem for Ideals

We prove cancellation theorems for special ideals in Gorenstein local rings. These theorems take the form that if KI ⊆ JI, then K ⊆ J.

A Cancellation Theorem for BCCSP

This paper presents a cancellation theorem for the preorders in van Glabbeek’s linear time-branching time spectrum over BCCSP. Apart from having some intrinsic interest, the proven cancellation result plays a crucial role in the study of the cover equations, in the sense of Fokkink and Nain, that characterize the studied semantics. The techniques used in the proof of the cancellation theorem ma...

Cancellation Theorem Vladimir

In this paper we give a direct proof of the fact that for any schemes of finite type X , Y over a Noetherian scheme S the natural map of presheaves with transfers Hom(Ztr(X),Ztr(Y )) → Hom(Ztr(X)⊗tr Gm,Ztr(Y )⊗tr Gm) is a (weak) A-homotopy equivalence. As a corollary we deduce that the Tate motive is quasi-invertible in the triangulated categories of motives over perfect fields. 2010 Mathematic...

Walker's Cancellation Theorem

Walker’s cancellation theorem says that if B Z is isomorphic to C Z in the category of abelian groups, then B is isomorphic to C. We construct an example in a diagram category of abelian groups where the theorem fails. As a consequence, the original theorem does not have a constructive proof even if B and C are subgroups of the free abelian group on two generators. Both of these results contras...