Let X be a field with jXj 3. An algebra (X; ) is said to be quadratic if x y is
dened by x y = a1x2 + a2xy + a3y2 + a4x + a5y + a6, where a1; a2; a3; a4; a5; a6 2 X,
for any x; y 2 X. A quadratic algebra (X; ) is said to be a quadratic BP-algebra if it
satises the conditions (B1), (BP1) and (BP2).