def test__diff__3(self):
ring = PolyRing('x,y,v,w', True)
ring.ext_num_field('t^2 + 1')
x, y, v, w, a0 = ring.coerce('x,y,v,w,a0')
d1 = ring.diff(y**2 * x**3 - a0, x, 2)
d2 = ring.diff(d1, y, 2)
assert d1 == 6 * y**2 * x
assert d2 == 12 * x
def test__diff__2(self):
ring = PolyRing('x,y,v,w', True)
ring.ext_num_field('t^2 + 1')
x, y, v, w, a0 = ring.coerce('x,y,v,w,a0')
assert ring.diff(x**3 - a0, x, 3) == 6
def test__diff__1(self):
ring = PolyRing('x,y,v,w', True)
ring.ext_num_field('t^2 + 1')
x, y, v, w, a0 = ring.coerce('x,y,v,w,a0')
assert ring.diff(w - a0, w, 1) == 1