The following produces a ``tree-like'' rendering of object subst by displaying it as a prefix ternary-operator. It is a good rule for rendering complex subst objects once the listener is familiar with the concept of textual substitution. It is very succinct and conveys nesting effectively.
[LVerbatim1581]
where (reading-state 'dim-children) generates a new AFL state along dimension dim-children; see fig:children.