A point on the embedded elliptic curve
By definition, the base field of the embedded curve is the scalar field of the proof system curve, i.e the Noir Field.
x and y denotes the Weierstrass coordinates of the point.
Scalar for the embedded curve represented as low and high limbs
By definition, the scalar field of the embedded curve is base field of the proving system curve.
It may not fit into a Field element, so it is represented with two Field elements; its low and high limbs.