![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhaopfUINUX098WLBwoRf35qwFGXQU5UN6sGmd0tuVXR4wRm3z0PFwB64obhvn-POXrH65fYI9PstD5Gx7ty8axbLO4N-O7krIRCAl7ZjSnuMlMTxaY5mKleRMNdp5J_pNQJPnJ/s200/Tred-G.png)
the transitive reduction is:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtEkqMVgo3L6oyxUnGFf7RXS-8Bm4ja0AK9jL-xiGtrrqoNz8_0bOanD1IrsceZyRauWkNulFum3c17h_i6IKrBa26Lay5CRb6Ye01sHZIHClbAy1FcUhUzaaXC3hdwf-eBcLE/s200/Tred-Gprime.png)
Note that the original graph has an edge a -> d, but this is absent after the reduction because we can get from a to d via b (or c).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxG0ZdYeucPXSSsK6-dyOUAUsNTCen5G7_10FmG5gmdHW87Ij9KZorwT3XAkcuWe-9C2u3KnLTNyPswGkWgeI2iQQK0YEAvN-TAVuxz_CfpirTQO4osqs4aiRoEEqWcS2EwA1J/s200/Platyprotus.jpg)
What's the point? Well, it occurs to me that a quick way of harvesting information about existing taxonomies (e.g., if we want to assemble an all embracing classification of life to hep navigate a database) is to make use of the titles of taxonomic papers, e.g., the title Platyprotus phyllosoma, gen. nov., sp. nov., from Enderby Land, Antarctica, an unusual munnopsidid without natatory pereopods (Crustacea: Isopoda: Asellota) gives us:
Crustacea -> Isopoda -> Asellota ->Platyprotus -> phyllosoma
From the paper, and or other sources we can get paths such as Asellota -> Munnopsididae -> Platyprotus and Isopoda -> Munnopsididae. Imagine that we have a set of these paths, and want to assemble a classification (for example, we want to grow the Species 2000 classification, which lacks this isopod). Here's the graph:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmeNfYfIE3vpt1xCsanIJem0GoNxNUZ5KyYeKThRnkwv43BWOqGJw2QTOwMwQNUkr2wV_JDF-Sx6SUp_vcfESYxTu2bUEzZ09aP6CRlu6vY9hmPxNhNmNMa6hq1WqBFdlRBJIp/s320/g1.jpg)
This clearly gives us information on the classification of the isopod, but it's not a hierarchy. The transitive reduction, however, is:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjq6YvrRyxHD5m5IQiD8eZn1IjFJcHIHIoW8byTEQR0yRuPalCen1i0AdggXf-Tc8Z96gXFMTjpHqU7ubWZyA6iqRH5KLgGPgMO8X3QTj3coqoUqpvqdhdRRYdkDn6gDk4bRIvg/s320/g2.jpg)
It would be fun to explore using this technique to mine taxonomic papers and automate the extraction of classifications, as well as names.