Točka A

Prva koordinata točke A je

d is a half of a side of a square, centered at P, where random points B are chosen. 

Meaning of d

ε  is a measure of tolerance for point B to be visible. At the beggining no condition on B is given. 

Meaning of ε

Activating the animation in slider a we generate new random points B inside the square centered at P

Meaning of a

To start the applet right click the slider a and activate the animation. 
Then move the point P and change the value of d. 

a = -1.7 (slider from -5 to 5, step 0.1)
P = (3.395, 6.6882)
b: x(P)
tekst1 = Textfield(P)
tekst2 = Textfield(b)
d = 1.67 (slider from 0 to 2, step 0.01)
c = RandomUniform(x(P) - d + (0 * a), x(P) + d)
e = RandomUniform(y(P) - d + (0 * a), y(P) + d)
B: (c, e)
ε = 0.04 (slider from 0 to 0.2, step 0.01)
f = false
g = false
h = false