<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">1-\prod_{I=0}^{3}\left(\operatorname{sign}\left(\left(\max\left(\left|\left(3^{I}\left(x-.5\right)\right)-\operatorname{floor}\left(3^{I}\left(x-.5\right)\right)-.5\right|,\left|\left(3^{I}\left(y-.5\right)\right)-\operatorname{floor}\left(3^{I}\left(y-.5\right)\right)-.5\right|\right)-\frac{1}{6}\right)\right)+0\right)\ge0\left\{-.5&lt;x&lt;.5\right\}\left\{-.5&lt;y&lt;.5\right\}</pre></body></html>