{- boolean channels -}
type Boolean = ^[^[] ^[]]

{- true and false -}
def True b : Boolean = b?[t f] = t![]
and False b : Boolean = b?[t f] = f![]

{- check value of boolean located at the specified channel -}
def Check b : Boolean =
    (new t : ^[]
     new f : ^[]
     ( b![t f]
     | t?[] = print!"It's true"
     | f?[] = print!"It's false"))

{- negation of the boolean located at the first specified channel,
   located at the newly created second specified channel -}
def Not [b1 : Boolean b2 : Boolean] =
    b2?[t f] = b1![f t]

{- Conjunction of the booleans located at the first and second specified
   channel, located at the newly created third specified channel -}
def And [b1 : Boolean b2 : Boolean b : Boolean] =
    b?[t f] = 
    (new x:^[] 
     ( b1![x f]
     | x?[] = b2![t f]))
       
{- test of And -}
new b1 : Boolean {- false -}
new b2 : Boolean {- true -}
new b : Boolean  {- conjuction of b1 and b2 -}

run (False!b1 | True!b2 | And![b1 b2 b] | Check!b)