Free software versus software idea patents

[Terry Reedy]

On 4/11/2011 4:36 AM, rusi wrote:

> http://www.cse.uconn.edu/~dqg/papers/cie05.pdf
>
> may be of interest (and also other papers of Peter Wegner questioning
> the universality of Turing machines lambda calculus etc)

Thank you for that reference. In summary, it says that while Turing 
machine are universal for finite function calculations, infinite 
interactive processes are not (finite) function calculations, and 
therefore need an extension to TMs. This is pretty obviously correct.

Python iterators, and especially generators, implement the extension 
that the authors call 'persistent Turing machines' (PTMs, section 6.2), 
except that iterators (and generators by default) operate in 'pull' 
mode, while they describe PTMs as operating in 'push' mode (as with 
generator.send()).

-- 
Terry Jan Reedy