Formatting
Fix index
Remove unnecesary constraint
Add TFun
Formatting
Rename applyWrapped -> applyTy
Add accumTy
Doc
Add casting between Fun and TFun
Remove Arity constraint from HVector

I does more harm than good
Express sequence and sequenceA using accumTy
Express wrap/unwrap using accum/acuumTy and get rid of ArityFun

HG Введите сообщение фиксации. Строки, начинающиеся с 'HG:' будут удалены.
cast{T,}Fun need not to be type class methods