About Direct Summands of Projective Modules Over Laurent Polynomial Rings
About Direct Summands of Projective Modules Over Laurent Polynomial Rings
Suppose i is a local ring and R = A[X, X-1] is a Laurent polynomial ring.We prove that for projective Ä-modules P and Q with rank Q < rank P , if Q, is a direct summand of Pf for a doubly monic polynomial / then Q is also a …