[tex-k] Bug-report for the TeXbook: Not all non-primitive control-sequences are defined, ultimately, in terms of the primitive ones.

[ud.usenetcorrespondence at web.de]

Probably this has not yet been reported.

TeXbook, Chapter 3: Controlling TeX  says:
 
| About 300 of TeX’s control sequences are called primitive; these
| are the low-level atomic operations that are not decomposable
| into simpler functions. ***All other control sequences are 
| defined, ultimately, in terms of the primitive ones.*** For
| example, \input is a primitive operation, but \’ and \" are not;
| the latter are defined in terms of an \accent primitive.

I doubt that ***all other control sequences*** are defined,
ultimately, in terms of the primitive ones.

For example, with

   \def\mymacro{word}

the control sequence \mymacro is not defined in terms of "the
primitive ones" at all. 

The control sequence \mymacro is defined in terms of explicit
non-active character tokens only while explicit non-active
character tokens are not considered primitives.

Sincerely

Ukrich Diez