Texts discussed:

• Christopher Alexander (2001) The Nature of Order, Book 1: The Phenomenon of Life, Center for Environmental Structure, Berkeley, California.
• Christopher Alexander (2009) “Harmony-Seeking Computations”, Keynote Speech at the International Workshop “The Grand Challenge in Non-Classical Computation”, University of York, UK, April 2005
• Christopher Alexander, S. Ishikawa, M. Silverstein, M. Jacobson, I. Fiksdahl-King & S. Angel (1977) A Pattern Language. 
• Nikos Salingaros (2006; 2014) A Theory of Architecture. https://applied.math.utsa.edu/~yxk833/ATOA-online.html

Further reading: 

• Michael Mehaffy & Nikos Salingaros (2012) Frontiers of Design Science: Computational Irreducibility, Metropolis. Reprinted as Chapter 15 of Design for a Living Planet (2015). https://www.metropolismag.com/ideas/frontiers-of-design-science-computational-irreducibility/
• Todd Rowland (2021) Computational Irreducibility, MathWorld — A Wolfram Web Resource. https://mathworld.wolfram.com/ComputationalIrreducibility.html
• Nikos Salingaros (2012) Urbanism as Computation, in Juval Portugali, H. Meyer, E. Stolk & E. Tan, Eds., Complexity Theories of Cities Have Come of Age, Springer, Berlin, pages 245-268. Keynote speech at the “Complexity Theory of Cities” Conference, Delft, September 2009. https://applied.math.utsa.edu/~yxk833/urbanism-computation.pdf
• Stephen Wolfram (2002) “Computational Irreducibility”, A New Kind of Science, page 737. https://www.wolframscience.com/nks/p737--computational-irreducibility/