Version 0.2: 24 March 2011

  * Initial release to go along with submission of "Binders Unbound".

Version 0.2.1: 28 March 2011

  * Massive update to documentation.

Version 0.2.2: 29 March 2011

  * Add MonadFix instances for FreshM and LFreshM.  Thanks to Job
    Vranish for the suggestion.

Version 0.2.3: 20 April 2011

  * Fix minor bugs in
    - tutorial/Tutorial.lhs
    - examples/Abstract.hs
    - examples/STLC.hs

    Thanks to Ki Yung Ahn for the reports.

Version 0.2.5: 13 July 2011

  * Fix bug in mkPerm which caused unbind2 to unexpectedly fail when
    dealing with binders with non-disjoint sets of names.

    Thanks to Sean Leather for the report.

  * Clean up some compiler warnings.

Version 0.3: 24 August 2011

  * New permutation- and set-binding functions, for creating binders
    which don't care about the order of multiple bound names, and/or
    about unused bound names.

  * Bump RepLib dependency to 0.5, which now has support for GADTs
    without existential type variables.

Version 0.3.1: 25 August 2011

  * Update to build on GHC 7.2.1

Version 0.4: 15 March 2012

  * Update to build on GHC 7.4.1

  * add MonadWriter instances for FreshMT and LFreshMT

  * Make 'getAvoids' function into a method of the LFresh class

Version 0.4.0.1: 23 March 2012

  * Remove broken links from documentation

Version 0.4.0.2: 10 April 2012

  * Bump 'mtl' upper bound to allow mtl-2.1

Version 0.4.1: 5 June 2012

  * Patch from Vilhelm Sjöberg changing acompareR1 to return EQ for
    Abstract1

Version 0.4.1.1: 21 Aug 2012

  * Bump containers upper bound and test with GHC 7.6.1

Version 0.4.2: 15 July 2013

  * remove derived instances: MonadState for FreshMT and MonadReader
    for LFreshMT.  No one should have been using these anyway, and
    they made it impossible to use these transformers together with
    your own state.

  * added unbind variants [l]unbind{23}Plus for conveniently unbinding
    in a MonadPlus context.

Version 0.4.3: 29 January 2014

  * Add Binary instances for Name, GenBind, Rebind, and Embed.

    Note that although the PVP requires a major version bump for added
    instances, it was impossible to write these instances outside of
    the package, so there is no danger of breakage.

Version 0.4.3.1: 8 May 2014

  * Allow transformers-0.4 and mtl-2.2

Version 0.4.4: 18 May 2015

  * Update to work with GHC 7.10
  
Version 0.4.5: 2 Oct 2015

  * Test suite in cabal file
  * New optimized function for immediately substitution w/o naming
    Only works for patterns with a single variable:
      substBind :: Subst a b => Bind (Name a) b -> a -> b

Version 0.5: August 2016

  * Remove Show superclass for Alpha  (potentially breaking change)
  * Remove permValid function from Unbound.PermM
  
  * New function in Unbound.LocallyNameless.Ops
      patUnbind :: (Alpha p, Alpha t) => p -> Bind p t -> t		
  * More sensible Show instance for bind, shows as code that
    can be directly parsed to Haskell.
      old:  <a> (Var 0@0)
		new:  (bind (string2Name "a") (Var (string2Name "a"))
  * works with GHC-8.0.1
  * Error message if don't override aeq' / acompare' for abstract types
  * More correctness tests
  
Planned extensions:
  * Cache free variables at binders