 \vec{ i } 

 \vec{ j } 

 \vec{ a } 

 \vec{ b } 

O = Intersect(xAxis, yAxis)
A = Point(xAxis)
B = Point(yAxis)
u = Vector(O, A)
v = Vector(O, B)
C = (1, 2)
D = (5, 4)
a = Vector(C, D)
E = (-2, 3)
F = (-2, -1)
b = Vector(E, F)
xa: x(a)
ya: y(a)
xb: x(b)
yb: y(b)