BSD-3-Clause licensed and maintained by Ashley Yakeley
This version can be pinned in stack with:open-witness-0.4.0.1@sha256:da0e1c622b5e72825bda84d76565709710e4b01eb63af56d2a1d7f8cfb1f1386,2176

Open witnesses are witnesses that can witness to any type. However, they cannot be constructed, they can only be generated in the IO monad. See the paper Witnesses and Open Witnesses (http://semantic.org/stuff/Open-Witnesses.pdf).