Compiled towers

The discipline means that an established record is not edited. It is a restriction on internal gates, not on an external detecting effect. An external reversal circuit is allowed only through an interface containing all factors on which that circuit acts.

A partition into observer levels may be supplied, but the results depend on the final classes, not on the level names. A record designated at one level and copied once at each of $d-1$ later levels has $c=d$ members. Throughout this paper a $c$-member read-chain contains one root and $c-1$ copying events.