A x B = {(1 / 0.5), (1 / 1.5), (1 / 2.5),
              (2 / 0.5), (2 / 1.5), (2 / 2.5),
              (3 / 0.5), (3 / 1.5), (3 / 2.5)} 

R_1 = {(1 / 0.5), (1 / 1.5), (1 / 2.5),
                        (2 / 1.5), (2 / 2.5), 
                        (3 / 1.5), (3 / 2.5)} 

R_2 = {(1 / 0.5), 
                       (2 / 1.5), 
                                     (3 / 2.5)}

a = -17 (slider from -20 to 40, step 1)
A = (1, 0.5)
B = (1, 1.5)
C = (1, 2.5)
D = (2, 0.5)
E = (2, 1.5)
F = (2, 2.5)
G = (3, 0.5)
H = (3, 1.5)
I = (3, 2.5)
J = (1, 0.5)
K = (1, 1.5)
L = (1, 2.5)
M = (2, 1.5)
N = (2, 2.5)
O = (3, 1.5)
P = (3, 2.5)
Q = (1, 0.5)
R = (2, 1.5)
S = (3, 2.5)