## Elaborators

TODO. See [Lean Together 2021: Metaprogramming in Lean
4](https://youtu.be/hxQ1vvhYN_U) for an overview as well [the
continuation](https://youtu.be/vy4JWIiiXSY) about tactic programming.
For more information on antiquotations, see also §4.1 of [Beyond
Notations: Hygienic Macro Expansion for Theorem Proving
Languages](https://arxiv.org/pdf/2001.10490.pdf#page=11).