Changed the names of these two styles to what they really are: map reduce

31-double-map-reduce/README.md

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+Style #31
+==============================
+
+Very similar to style #30, but with an additional twist
+
+Constraints:
+
+- Input data is divided in chunks, similar to what an inverse multiplexer does to input signals
+
+- A map function applies a given worker function to each chunk of data, potentially in parallel
+
+- The results of the many worker functions are reshuffled in a way
+  that allows for the reduce step to be also parallelized
+
+- The reshuffled chunks of data are given as input to a second map
+  function that takes a reducible function as input
+
+Possible names:
+
+- Map-reduce 
+- Hadoop style
+- Double inverse multiplexer