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Question

Math 6310 • Algebra

Fall 2004 • Question 2

Let \(R\) be a commutative ring with identity. Given an \(R\)-module \(M\), recall the \(R\)-module \[ \bigwedge M=\bigoplus _{j\ge 0}\bigwedge ^j M, \] where \(\bigwedge ^j M\) is the \(j\)th exterior power of \(M\). Define a natural operation on morphisms so that the assignment \(M\mapsto \bigwedge M\) becomes a functor and determine whether this functor is exact.

Raw LaTeX

Let \(R\) be a commutative ring with identity. Given an \(R\)-module \(M\), recall the \(R\)-module
\[
\bigwedge M=\bigoplus_{j\ge 0}\bigwedge^j M,
\]
where \(\bigwedge^j M\) is the \(j\)th exterior power of \(M\). Define a natural operation on
morphisms so that the assignment \(M\mapsto\bigwedge M\) becomes a functor and determine whether
this functor is exact.