Contracted ideals and purity for ring extensions
Contracted ideals and purity for ring extensions
In this paper an example is given of a pair of commutative noetherian rings <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper R subset-of-or-equal-to upper S"> <mml:semantics> <mml:mrow> <mml:mi>R</mml:mi> <mml:mo>⊆</mml:mo> <mml:mi>S</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">R \subseteq S</mml:annotation> </mml:semantics> </mml:math> </inline-formula> with <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper S"> <mml:semantics> <mml:mi>S</mml:mi> <mml:annotation encoding="application/x-tex">S</mml:annotation> </mml:semantics> </mml:math> </inline-formula> …