% superfig golden example 3 -- a state/time flow.
% One decode step: previous KV plus a new token produce the next state
% and the emitted token. The callout is an aside on the finished state band.
%   ../scripts/build.sh state-flow.tex
\documentclass[border=10pt]{standalone}
\usepackage[cjk]{superfig}

\sfsetrole{state}{sfTeal}
\sfsetrole{step}{sfOrange}
\sfsetrole{tok}{sfViolet}

\begin{document}
\begin{tikzpicture}

\sfstage{S}{解码一步：旧状态 + 新 token}
\sfvgap{26mm}
\sfrow{R1}{14mm}
  \sfnode[role=state]{kv}{KV$_t$}{16mm}{11mm}
  \sfconn{c1}{读}
  \sfnode[role=step]{dec}{解码}{16mm}{11mm}
  \sfconn{c2}{追加}
  \sfnode[role=state]{kv2}{KV$_{t+1}$}{18mm}{11mm}
\sfrowend
\sflane{R1}
\sfcaption{kv}{KV$_t$}{已缓存键值}
\sfcaption{dec}{一步}{读 KV，写新列}
\sfcaption{kv2}{KV$_{t+1}$}{状态推进}
\sfcallout{N1}{38mm}{R1}{为何保留 KV}{%
  下一步只读已有列、只追加 $x_t$ 这一列。重算前缀是另一条路径，这张图不画。}

% Tokens enter from above so the caption lane below the state row stays clear.
\sfnode[role=tok, at={($(dec.north west)+(-4mm,14mm)$)}]{xt}{$x_t$}{14mm}{10mm}
\sfnode[role=tok, at={($(dec.north east)+(4mm,14mm)$)}]{yt}{$y_t$}{14mm}{10mm}
\sfarrow{xt.south}{dec.north}
\sfarrow{dec.north}{yt.south}

\sfbbox{all}
\sftopformula{F}{%
  $(\mathrm{KV}_{t+1},\, y_t) = \mathrm{Decode}(\mathrm{KV}_t,\, x_t)$}
\sfmeaningbox{mb}{108mm}{all}
  {自回归一步：状态沿时间推进}
  {缓存 KV、解码算子、本步 token}
  {解码读 $\mathrm{KV}_t$ 与 $x_t$，写出 $y_t$，并把新列追加为 $\mathrm{KV}_{t+1}$}

\end{tikzpicture}
\end{document}