[Haskell-beginners] Control.Monad.State: State CTOR unneeded to create a State?

[Larry Evans]

Page:

  
http://hackage.haskell.org/packages/archive/mtl/latest/doc/html/Control-Monad-State.html#2

suggests, with the content:

  Constructors
    State    
      runState :: (s -> (a, s))    

that State has a labeled constructor:

  http://www.haskell.org/onlinereport/exps.html#sect3.15.2
 
yet the Examples section:

  
http://hackage.haskell.org/packages/archive/mtl/latest/doc/html/Control-Monad-State.html#4
 
shows, AFAICT, no call to the State CTOR:

  tick :: State Int Int
  tick = do n <- get
            put (n+1)
            return n
            
I assume the n must be an Int (since it's in n+1), but what are the
get and put.  There is a get and put described here:

  
http://hackage.haskell.org/packages/archive/mtl/latest/doc/html/Control-Monad-State.html#1
 
however, I don't see how they are relevant since they are defined for
an already existing MonadState, and AFAICT, tick hasn't been defined
yet since it's on the lhs of the =.

Please, what am I missing?

TIA

-regards
Larry