IHaskellDisplay class,
+each type used in a variable must have a type class instance
+that allows automatic conversion into the alternative representation.
+If you don't need this feature, simply choose () as the alternative
+representation type.
+The graph of alternative representations can be extracted from
+the variable store. We provide code to assemble the store into a
+spreadsheet (of static cells). Foldable structures
+of basic values become columns while doubly-nested structures
+become tables.
+
+
+Example
+=======
+
+Continuing the example above, in the Provenience monad you would
+write something like the following. Of course it is up to the programmer
+to decide how fine-grained the decomposition into Provenience actions
+should be.
+
+ workflow x' y' = do
+ ---------- register and render the input variables ------------------
+ x <- input x' -- register and render x'
+ y <- input y'
+ x `named` "x" -- links to x show "x" as text
+ y `named` "y"
+ x x
+ b <- func g (renderDefault "auxiliary function g") <%> a <%> y
+ c <- func h (renderDefault "auxiliary function h") <%> a <%> b
+ ------ only book-keeping below --------------------------------------
+ ---------------------------------------------------------------------
+ a `named` "a" >> b `named` "b" >> c `named` "result"
+ a > render b >> render c
+ return c
+
+Above, the action `func` registers a new variable and immediately
+supplies a description, which is then used as edge label by the
+`<%>` operator on the same line.
+You see that instead of one line of pure Haskell you are burdened
+with writing four kinds of Provenience actions:
+*register*, *describe*, *alias* and *render*. But of the four actions,
+three are only concerned with providing descriptions that the pure code
+did not contain.
+
+Remarks
+=======
+
+This package was inspired by the
+[Javelin](https://en.wikipedia.org/wiki/Javelin_Software "wikipedia")
+Software. Thanks to John R Levine, one of the authors of Javelin,
+for explaining the concepts underlying Javelin.
+
+By using [Pandoc](https://hackage.haskell.org/package/pandoc "pandoc")
+the user has a number of output format choices.
+With a little CSS, the above example may be rendered like follows.
+Unfortunately, hackage does not allow raw html in markdown, so
+you have to convert the markdown yourself.
+
+(For the sake of example,
+we used `f = abs`, `g = replicate` and `h = fmap concat . replicate`).
+
+a
+Sources:
+Construction:
+auxiliary function f applied to x
+Used in:
+first intermediate result
+4
+b
+Sources:
+Construction:
+auxiliary function g
+Used in:
+second intermediate result
+tttt
+