| mapAccum | Control.Monad.Trans.Accum | 
| mapAccumT | Control.Monad.Trans.Accum | 
| mapCont | Control.Monad.Trans.Cont | 
| mapContT | Control.Monad.Trans.Cont | 
| mapExcept | Control.Monad.Trans.Except | 
| mapExceptT | Control.Monad.Trans.Except | 
| mapIdentityT | Control.Monad.Trans.Identity | 
| mapLift | Control.Applicative.Lift | 
| mapMaybeT | Control.Monad.Trans.Maybe | 
| mapReader | Control.Monad.Trans.Reader | 
| mapReaderT | Control.Monad.Trans.Reader | 
| mapRWS |   | 
| 1 (Function) | Control.Monad.Trans.RWS.CPS | 
| 2 (Function) | Control.Monad.Trans.RWS.Lazy, Control.Monad.Trans.RWS | 
| 3 (Function) | Control.Monad.Trans.RWS.Strict | 
| mapRWST |   | 
| 1 (Function) | Control.Monad.Trans.RWS.CPS | 
| 2 (Function) | Control.Monad.Trans.RWS.Lazy, Control.Monad.Trans.RWS | 
| 3 (Function) | Control.Monad.Trans.RWS.Strict | 
| mapSelect | Control.Monad.Trans.Select | 
| mapSelectT | Control.Monad.Trans.Select | 
| mapState |   | 
| 1 (Function) | Control.Monad.Trans.State.Lazy, Control.Monad.Trans.State | 
| 2 (Function) | Control.Monad.Trans.State.Strict | 
| mapStateT |   | 
| 1 (Function) | Control.Monad.Trans.State.Lazy, Control.Monad.Trans.State | 
| 2 (Function) | Control.Monad.Trans.State.Strict | 
| mapWriter |   | 
| 1 (Function) | Control.Monad.Trans.Writer.CPS | 
| 2 (Function) | Control.Monad.Trans.Writer.Lazy, Control.Monad.Trans.Writer | 
| 3 (Function) | Control.Monad.Trans.Writer.Strict | 
| mapWriterT |   | 
| 1 (Function) | Control.Monad.Trans.Writer.CPS | 
| 2 (Function) | Control.Monad.Trans.Writer.Lazy, Control.Monad.Trans.Writer | 
| 3 (Function) | Control.Monad.Trans.Writer.Strict | 
| MaybeT |   | 
| 1 (Type/Class) | Control.Monad.Trans.Maybe | 
| 2 (Data Constructor) | Control.Monad.Trans.Maybe | 
| maybeToExceptT | Control.Monad.Trans.Maybe | 
| modify |   | 
| 1 (Function) | Control.Monad.Trans.RWS.CPS | 
| 2 (Function) | Control.Monad.Trans.RWS.Lazy, Control.Monad.Trans.RWS | 
| 3 (Function) | Control.Monad.Trans.RWS.Strict | 
| 4 (Function) | Control.Monad.Trans.State.Lazy, Control.Monad.Trans.State | 
| 5 (Function) | Control.Monad.Trans.State.Strict | 
| modify' |   | 
| 1 (Function) | Control.Monad.Trans.State.Lazy, Control.Monad.Trans.State | 
| 2 (Function) | Control.Monad.Trans.State.Strict | 
| modifyM |   | 
| 1 (Function) | Control.Monad.Trans.State.Lazy, Control.Monad.Trans.State | 
| 2 (Function) | Control.Monad.Trans.State.Strict | 
| MonadTrans | Control.Monad.Trans.Class |