\vec t

v_♢

\vec{ t}\,^*

\vec{v}^{\,*}

\vec e_1

\vec e_2

G^*

\partial G^*

G

\partial G

\vec t

\vec v

\vec v_♢

\partial G

\vec v_\bot

gl1: (0.14285714285714285 * x^(4)) + ((0.2 * x^(2)) * y) + x^(2) - ((0.058823529411764705 * x) * y^(2)) + (2 * y^(2)) = 1
a(x, y) = If[(x - 2)^(2) + (y - 2.5)^(2) ≤ 4, ((-(x - 2)^(2))) / 4 - (y - 2.5)^(2) / 5 + 1 + y / 4]
b_2 = CurveCartesian(2 + (2 * cos(t)), 2.5 + (2 * sin(t)), a(2 + (2 * cos(t)), 2.5 + (2 * sin(t))), t, 0, (2 * π))
xP = 2.5
yP = 2
P: (xP, yP, a(xP, yP))
a_x = Derivative(a(x, y), x)
a_y = Derivative(a(x, y), y)
φ_u = Vector(P, P + (1, 0, a_x(x(P), y(P))))
φ_v = Vector(P, P + (0, 1, a_y(x(P), y(P))))
A: P + (1, 1, a_x(x(P), y(P)) + a_y(x(P), y(P)))
B = Point(P, φ_u)
C = Point(P, φ_v)
v1, b, b_1, a_1, c = Polygon(P, B, A, C)
D = (3.6001927882529046, 2.2708054190849865, 2.5)
f = OrthogonalLine(P, v1)
v = Vector(P, D)
g = OrthogonalLine(D, f, space)
h = OrthogonalLine(D, v1)
E = Intersect(g, f)
F = Intersect(h, v1)
v_Δ = Vector(P, F)
v_⟂ = Vector(P, E)
i = Segment(D, F)
j = Segment(E, D)
Pst = (-0.2250864197530851, -0.10108641975308932)
u = Vector(Pst, Pst + (0.5, 0))
w = Vector(Pst, Pst + (0, 0.5))
G = (0.19644444444444595, 0.2552592592592563)
d = Vector(Pst, G)
H = Point(gl1)
k = Tangent(H, gl1)
I = Point(k)
e = Vector(H, I)
J = Point(b_2)
l = Tangent(J, b_2)
K = Point(l)
t = Vector(J, K)
L = (-0.5490632932786876, -1.2383483684485017)
M = (-0.10836081665492547, -1.2383483684485017)