Closed hulls in infinite symmetric groups
Closed hulls in infinite symmetric groups
Let <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper S y m upper M"> <mml:semantics> <mml:mrow> <mml:mi>Sym</mml:mi> <mml:mo><!-- --></mml:mo> <mml:mi>M</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">\operatorname {Sym} M</mml:annotation> </mml:semantics> </mml:math> </inline-formula> be the symmetric group of an infinite set <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper M"> <mml:semantics> <mml:mi>M</mml:mi> <mml:annotation encoding="application/x-tex">M</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. What is the …