The Normal function is a placeholder for representing a normal form for an expression. It is used in conjunction with mod and evala as described below which defines the coefficient domain.

The call  Normal(a) mod p computes a normal form for a where a is a rational expression over a finite field.

The call  evala(Normal(a))  computes a normal form for a where a may contain algebraic coefficients defined by RootOfs or radicals. See evala,Normal for more information.

Normal( (x^3-2*x^2+2*x+1)/(x^4+1) ) mod 5;

$\frac{x+3}{x^2+3}$

evala(Normal( (x^2-2)/(x-RootOf(_Z^2-2)) ));

$x+\mathrm{RootOf}\left({\mathrm{\_Z}}^2-2\right)$