+sq3 = Le(0, x) & Le(x, 3) & Le(0, y) & Le(y, 3)
+sq4 = Le(1, x) & Le(x, 2) & Le(1, y) & Le(y, 2)
+sq5 = Le(1, x) & Le(x, 2) & Le(1, y)
+sq6 = Le(1, x) & Le(x, 2) & Le(1, y) & Eq(y, 3)
+u = Polyhedron([])
+x = sq1 - sq2
+
+print('sq1 =', sq1) #print correct square
+print('sq2 =', sq2) #print correct square
+print('sq3 =', sq3) #print correct square
+print('sq4 =', sq4) #print correct square
+print('u =', u) #print correct square
+print()
+print('¬sq1 =', ~sq1) #test compliment
+print()
+print('sq1 + sq1 =', sq1 + sq2) #test addition
+print('sq1 + sq2 =', Polyhedron(sq1 + sq2)) #test addition
+print()
+print('u + u =', u + u)#test addition
+print('u - u =', u - u) #test subtraction
+print()
+print('sq2 - sq1 =', sq2 - sq1) #test subtraction
+print('sq2 - sq1 =', Polyhedron(sq2 - sq1)) #test subtraction
+print('sq1 - sq1 =', Polyhedron(sq1 - sq1)) #test subtraction
+print()
+print('sq1 ∩ sq2 =', sq1 & sq2) #test intersection
+print('sq1 ∪ sq2 =', sq1 | sq2) #test union
+print()
+print('sq1 ⊔ sq2 =', Polyhedron(sq1 | sq2)) # test convex union