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ArrCharPoly    --    characteristic polynomial of an arrangement of hyperplanes


Syntax 
ArrCharPoly(A: LIST): RINGELEM

Description
This function returns the characteristic polynomial from the list A of hyperplanes in the arrangement in the variable t.

Example 
/**/ use QQ[x,y];	
/**/ A := [x, x-y, y];
/**/ ArrCharPoly(A);
t^2 -3*t +2
/**/ RingOf(ArrCharPoly(A));
RingWithID(4, "QQ[t]")

/**/ use ZZ/(5)[x,y];	
/**/ A := [x, x-y, y];
/**/ ArrCharPoly(A);
t^2 -3*t +2
/**/ RingOf(ArrCharPoly(A));
RingWithID(4, "QQ[t]")

See Also