A short update: Einstoff has since been reworked from the original proof of concept into a staged compiler. The familiar WL-pattern surface remains, but descriptions are now captured into an inert internal representation, solved as explicit shape constraints, analyzed per operator, and lowered through a shared execution plan. This also brought clearer binding and hygiene rules, inline axis sizes via Annotation/Labeled, and pairwise within-tensor contraction. The current development version is 0.2.0, backed by more than 600 Wolfram and Python cross-validation tests; feedback on whether the surface notation feels idiomatic is still very welcome.

Any feedback or criticism is much appreciated!