Acknowledgments

I thank P. Amusuo, B. Çakar, R. Calvo, A. Cha, A. Chlipala, H. Davis, K. Davis, N. Davis, R.M. Davis, R.W. Davis, W. Davis, N. Eliopoulos, S. France, P. Jajal, K. Kalu, A. Kazerouni, J. Laredo, H. Peng, N. Pond, E. Snible, G.K. Thiruvathukal, and E. Wittern for their contributions, conversations, and help in making this book.

This work was supported by the U.S. National Science Foundation under grants #2541917 and #2452533.