tenkz

Tensor-network diagrams from a description of the network.

tenkz is a LaTeX package that draws matrix product states, tensor trains, PEPS sheets, string diagrams, and channel sandwiches from a statement of what the network is. An author writes down the tensors, their indices, and how the indices meet; the drawing measures where the ink goes. No coordinates and no lengths appear in a picture source.

This repository is the package, its manual, regression corpus, and release tools. It was extracted from TNLean, which still consumes the package to render blueprint pictures.

\begin{tenkz}[cols=2]
  \tn[ports={180:virtual:$\alpha$, 90:physical:$i_1$}]{A} &
  \tn[ports={0:virtual:$\beta$, 90:physical:$i_2$}]{B}
\end{tenkz}

The two tensors are chained by &, the bond between them is drawn because their adjacent index slots meet, and the open indices are the ones the source names.

While drawing, tenkz writes an event stream recording the structure it resolved. Checking tools read that stream to confirm that a printed picture and the contraction it claims to show agree.

• LaTeX2e with expl3 (TeX Live 2023 or later)
• pgf/TikZ
• hobby and spath3 (separate CTAN packages; missing either fails at load)

The corpus, manual, and reference figures are built with XeTeX.

# Language registry and shrink ratchet
python3 scripts/tenkz_language.py check
python3 scripts/tenkz_shrink.py gate --base-ref origin/main

# Regression corpus and golden event streams
scripts/tenkz_corpus.sh
scripts/tenkz_golden.sh --check

# Compact manual: examples doctested, then a reproducible build
python3 scripts/tenkz_manual_doctest.py
python3 scripts/tenkz_manual_build.py check --require-engine

Operational detail lives in docs/tenkz/HACKING.md. The public language is docs/tenkz/LANGUAGE.md.

Put the files under tex/tenkz/ on TEXINPUTS, or in a local texmf tree under tex/latex/tenkz/. Then \usepackage{tenkz} binds the tenkz and tenkzeq environments.

A CTAN staging archive is built by python3 scripts/tenkz_ctan.py archive.

Open package work here. Open issues were transferred from TNLean at the split; the old TNLean URLs redirect. One TNLean issue remains because it edits blueprint sources, not this package: LionSR/TNLean#5693.

The library tracker is #10. Issue numbers cited in DESIGN.md / SOAK-1.0.md are the original TNLean numbers and still resolve through those redirects.

Apache License, Version 2.0. See LICENSE.

Version 0.7, released 2026-07-22. The change record is docs/tenkz/CHANGES.md.