The most interesting discussions to me are in the first link: specifically, the limitations surrounding the use of pattern matching for the type system, the limitation of limiting UpValues to a single depth, and the analysis of the 'infinite' evaluation model.
Comments
RE: My failed tweets,
Richard Fateman's reviews of Mathematica are at:
http://www.cs.berkeley.edu/~fateman/papers/mma.pdf http://www.cs.berkeley.edu/~fateman/papers/mma6rev.pdf
MockMMA is at http://www.cs.berkeley.edu/~fateman/mma1.6/
The most interesting discussions to me are in the first link: specifically, the limitations surrounding the use of pattern matching for the type system, the limitation of limiting UpValues to a single depth, and the analysis of the 'infinite' evaluation model.