class Functor < Type -> Type

class Monad < Functor

type List : Monad

vars a, b : Type

var m : Monad

op fail : m a

op return : a -> m a

var f : Functor

op fmap : (a -> b) -> f a -> f b

op empty : List a

type Set : Functor

op emptySet : Set a

. fail = "";

op map : (a -> b) -> List a -> List b

op __bind__ : m a * (a -> m b) -> m b

var g : a -> b

var x : m a

. fmap g = map g

. fmap g x = x bind \ y : a .! return (g y);

classes

Functor < Type -> Type;

Monad < Type -> Type

class

Monad < Functor

types

List : Monad;

Set : Functor

vars

a : Type %(var_1)%;

b : Type %(var_2)%;

f : Functor %(var_4)%;

m : Monad %(var_3)%

op __bind__ : forall a : Type; b : Type; m : Monad

. m a * (a -> m b) -> m b

op empty : forall a : Type . List a

op emptySet : forall a : Type . Set a

op fail : forall a : Type; m : Monad . m a

op fmap : forall a : Type; b : Type; f : Functor

. (a -> b) -> f a -> f b

op map : forall a : Type; b : Type . (a -> b) -> List a -> List b

op return : forall a : Type; m : Monad . a -> m a

vars

g : a -> b;

x : m a

. fail = ""

forall a : Type; b : Type; g : a -> b . fmap g = map g

forall a : Type; b : Type; m : Monad; g : a -> b; x : m a

. fmap g x = x bind \ y : a .! return (g y)

7.5: ### Hint: is type variable 'a'

7.8: ### Hint: is type variable 'b'

9.5: ### Hint: is type variable 'm'

15.5: ### Hint: is type variable 'f'

25.3-25.17: ### Hint:

constrain 'Set : Monad' is unprovable of '(op fail : forall a : Type; m : Monad . m a)

= (op emptySet : forall a : Type . Set a)'

known kinds are: {Functor}

25.8: *** Error: no typing for 'fail = emptySet'

27.8: *** Error:

in term '(op fail : forall a : Type; m : Monad . m a)

= (op empty : forall a : Type . List a)'

are uninstantiated type variables

'[_v13_a]'

31.15-31.17: ### Hint:

no kind found for 'm a'

expected: {Cpo}

found: {Type}

31.15-31.17: ### Hint:

no kind found for 'm a'

expected: {Cppo}

found: {Type}

33.7: ### Hint: not a class 'a'

33.7: ### Hint: not a class 'b'

33.23: ### Hint: not a kind 'm a'