Changes from the paper

pyrtree/expr.py

pyrtree/rtree.py

rtree/.hspec

rtree/test/expected/double-let-expr-ireda

rtree/test/expected/double-overloading-let-expr-ireda

rtree/test/expected/small-let-expr-ireda

rtree/test/expected/small-opr-expr-ireda

rtree/test/paper-examples/words

rtree/test/paper-examples/words'

rtree/test/src/Control/Monad/IRTreeSpec.hs

rtree/test/src/Control/Monad/RTreeSpec.hs