What’s the equivalent of this py_ecc code for untwisting the ʙɴ128 curve in Pari/ɢᴘ ?

[Laël Cellier <lael.cellier@gmail.com>]

Simple, I’ve curve defined as Y2=X3+3i+9 definied over finite finite field F2p=Fp[i]i2+1 with p=21888242871839275222246405745257275088696311157297823662689037894645226208583 and point X=11559732032986387107991004021392285783925812861821192530917403151452391805634×i+10857046999023057135944570762232829481370756359578518086990519993285655852781 Y=4082367875863433681332203403145435568316851327593401208105741076214120093531×i+8495653923123431417604973247489272438418190587263600148770280649306958101930

As this curve is homomorphic to the curve Y2=X3+3

    defined over F12p,
    how to convert the point to the F12p

curve such as the discrete logarithm relation between 2 points on the 1^st curve is preserved ?

I’ve following code from py_ecc :

def twist(pt: Point2D[FQP]) -> Point2D[FQ12]:
    _x, _y = pt
    # Field isomorphism from Z[p] / x**2 to Z[p] / x**2 - 18*x + 82
    xcoeffs = [_x.coeffs[0] - _x.coeffs[1] * 9, _x.coeffs[1]]
    ycoeffs = [_y.coeffs[0] - _y.coeffs[1] * 9, _y.coeffs[1]]
    # Isomorphism into subfield of Z[p] / w**12 - 18 * w**6 + 82,
    # where w**6 = x
    nx = FQ12([int(xcoeffs[0])] + [0] * 5 + [int(xcoeffs[1])] + [0] * 5)
    ny = FQ12([int(ycoeffs[0])] + [0] * 5 + [int(ycoeffs[1])] + [0] * 5)
    # Divide x coord by w**2 and y coord by w**3
    return (nx * w**2, ny * w**3)

but what it’s Pari/ɢᴘ equivalent ?