adding memory.lhs as new chapter
adding memory.lhs as new chapter

ssaavedra/liquidhaskell,ucsd-progsys/liquidhaskell,ucsd-progsys/liquidhaskell,ucsd-progsys/liquidhaskell,ssaavedra/liquidhaskell,ssaavedra/liquidhaskell,ucsd-progsys/liquidhaskell,ucsd-progsys/liquidhaskell,ssaavedra/liquidhaskell,ssaavedra/liquidhaskell,ucsd-progsys/liquidhaskell,ssaavedra/liquidhaskell