On 08/07/2020 14:46, John Cowan wrote:
> No, and I don't know of any other representation that has them except CL
> and R7RS S-expressions.

I think YAML has them - it has anchors and references although the
examples of them I find are purely for sharing common subexpressions, so
the language spec may disallow loops or something:

https://support.atlassian.com/bitbucket-cloud/docs/yaml-anchors/

--
Alaric Snell-Pym   (M7KIT)
http://www.snell-pym.org.uk/alaric/