Free coalgebras in a category of rings
Free coalgebras in a category of rings
Let <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="script upper R"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi class="MJX-tex-caligraphic" mathvariant="script">R</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">\mathcal {R}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> be the category of commutative rings with unity and unity-preserving homomorphisms, and let <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="normal upper Pi"> <mml:semantics> <mml:mi mathvariant="normal">Π</mml:mi> <mml:annotation encoding="application/x-tex">\Pi</mml:annotation> </mml:semantics> </mml:math> </inline-formula> be …