f(1, 2, 3, 4)
f(p1 = 1, 2, 3, 4)
f(p1 = 1, p2 = 2, p3 = 3, 4)
f(p1 = 1, p2 = 2, p3 = 3, p4 = 4)
f(1, 2, 3, p4 = 4)