how to implementation latent semantic indexing in python..

Alex Martelli aleax at
Thu Jul 19 03:59:13 CEST 2007

Tim Churches <tchur at> wrote:

> malkarouri wrote:
> > On 13 Jul, 17:18, 78ncp <santi_a... at> wrote:
> >> hi...
> >> how to implementation algorithm latent semantic indexing in python
> >> programming...??
> > 
> > Of course you are aware that LSA is patented..
> There is a US patent on it, sealed in 1989, but is it patented in any
> other countries? There is no such thing as a "global patent" - patents
> only cover the country which issues them. There is a global patent
> application process (the Patent Co-operation Treaty), but that just
> establishes a priority date for the invention in each country, but the
> inventor still needs to file patent applications and have them approved
> (sealed)  is each and every country. Did Bellcore do that back in the 1980s?

Aren't patents supposed to last 17 years, anyway?  A patent granted in
1989 should have expired in 2006, I believe (though IANAL, so...).


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