This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Bordermatrix. en The bordermatrix function was not working with the built in LaTeX interpreter on so have included screen capture of what the example actually generates br with LaTeX own Winfree LaTeX Mathematical formulas
Page 2023 Free-images.com. All images are Public Domain