# Can anyone guess what InternalRadicalMemberQ does?

There is an undocumented function InternalRadicalMemberQ which takes two arguments. But whatever input I try for the two arguments, it seems to crash the kernel (Mathematica 10.3 on Mac OS X). Can anyone guess what the function does based on the name of this function?

InternalRadicalMemberQ[Sqrt[x], x]           (*Kernel crash*)

InternalRadicalMemberQ[a x^2 + 2 x - b, x]   (*Kernel crash*)

• InternalRadicalMemberQ["Saul Alinsky"]? – ciao Jun 12 '16 at 9:04
• @ciao Maybe this can help. :) – yode Jun 12 '16 at 10:37
• here are some uses that do not crash(10.1): InternalRadicalMemberQ[Pi, Sqrt[2]] (*False*) InternalRadicalMemberQ[2, Sqrt[2]] (*True*) – george2079 Jun 12 '16 at 17:00
• @ciao So sorry I missed that comment last year. – Daniel Lichtblau Jul 30 '17 at 20:11

InternalRadicalMemberQ[x y, {x^2 y, x y^3}]
`
which means that $x y$ belongs to the radical of the polynomial ideal generated by $x^2 y$ and $x y^3$.