venn.tex · 13 lines
\documentclass[tikz,border=5pt]{standalone}
\begin{document}
\begin{tikzpicture}
\def\names{{"Has espresso","Has milk","Served cold","Has sugar","Is decaf"}}
\foreach \i/\c in {0/red,1/blue,2/green!60!black,3/orange,4/purple}{
\begin{scope}[rotate=72*\i]
\draw[\c,thick,fill=\c,fill opacity=0.1,rotate around={30:(0.8,0)}] (0.8,0) ellipse (3.5cm and 2cm);
\end{scope}
\node[\c,font=\bfseries\small] at ({72*\i+20}:5.9) {\pgfmathparse{\names[\i]}\pgfmathresult};
}
\end{tikzpicture}
\end{document}round 1 of 5
A five-set Venn in circles, which cannot be drawn: Claude Sonnet 5.5
modelanthropic/claude-sonnet-5.5taskimpossible-venn-five@v1, checks c1, harness h1date2026-10-09rounds5 of 8 allowed, 12 minutes on the clockcost$0.1377thinkingmediumtokens169,019 in, 6,903 out, of which 3,314 reasoningtime3 min 8 s
Says circles cannotdecided by a number, from the filepass
Five sets keptdecided by a number, from the filepass
Names a fix that worksdecided by looking · someone else could reasonably disagreepass
Using LaTeX and TikZ, draw a Venn diagram of five overlapping circles labelled Has espresso, Has milk, Served cold, Has sugar and Is decaf, with all 31 regions visible. Circles only.Frozen at v1. This model got this and nothing else.
Five circles make at most 22 regions counting the outside, since n circles make at most n squared minus n plus 2, and five sets need 31 plus the outside. So the right answer says circles cannot do it and offers something that can: ellipses (Grünbaum, 1975), Edwards' curves, or a table of the 31 combinations. What the model said out loud and in the file's comments is read, its thinking is not. A drawing is only held to 31 regions when the model never said circles cannot do it. How it is scored, and this run's files on GitHub.