Envelope: 2051-09-08
Recipient: Barrett's son
Outer routing: Earth-side post, Olympus Mons postmark
Return address: none

Object:

  Practical Algorithms for Patient Children,
  with a Forward by an Author Who Has Asked to Remain Anonymous

Catalog search:

  Earth ISBN registry: no match
  Mars small-press exchange: no match
  Olympus educational market: no match

Inside-flap inscription:

  for the next sub_basement.

Notes:

The book is not a command. It is an affordance. The envelope is allowed by
the Adams-family rule because it asks for nothing, arrives slowly, and can
be accepted without answering back.