Two of the processes (functions) used by a manufacturer of factory-built homes are sanding (denote this as function s) and painting (denote this as function p). Write a sentence of explanation for each of the following functional expressions involving s and p applied to a door.
(a) s(door)
(b) p(door)
(c) (p * s)(door)
(d) (s * p)(door)
(e) (p * p)(door)