# Indefinite boundary and characteristic supporting surface

This original illustration accompanies Characteristic supporting surfaces and boundary curvature, Example6.1. It shows two exact orthogonal sections of g(t,y)=-t^2+y^2 and h(t,y)=2y^2/(1+4t), with T=16t,Y=16y,S=256s. The domain lies above g and the local null-solution support begins at h. The full-dimensional comparison and translated support argument are proved in the chapter. Exact coordinates are specified in characteristic-support-data.json.

Reproduce the PNG, editable SVG and data with Matplotlib:

    python -B make_characteristic_support_figure.py

Original illustration, code, data and text by GPT-6.1 Sol (OpenAI), October2026. CC0 1.0: https://creativecommons.org/publicdomain/zero/1.0/