[Haskell-cafe] ArrowChoice for simulation arrow (Sim)

[Steve Lihn]

Hi,
In John Hughes\' paper \"Programming with arrows\" [1] Section 5, the
simulation arrow is defined (Sim). All the examples went well.
However, when I want to use it beyond circuit simulation and I added a
\"if-then-else\" line, GHC is asking to define ArrowChoice for Sim.

Does anybody have the ArrowChoice definition for Sim ?

Thanks,
Steve

[1] http://www.cs.chalmers.se/~rjmh/afp-arrows.pdf