a = 1 (slider from -6 to 6, step 0.1)
b = 4 (slider from -6 to 6, step 0.1)
f(x) = (a * x) + b
c = -1 (slider from -6 to 6, step 0.1)
d = -2 (slider from -6 to 6, step 0.1)
g(x) = (c * x) + d
e(x, y) = y < f(x)
h(x, y) = y ≥ g(x)