free type Bool ::= False | True

op And : Bool -> (? Bool) -> Bool

var x : ? Bool

. And False x = False

. And True x = x

. And False True = False; %implied

type

Bool : Type %[free type Bool ::= False | True]%

op And : Bool -> ? Bool -> Bool %(op)%

op False : Bool %(constructor)%

op True : Bool %(constructor)%

var

x : ? Bool

free type Bool ::= False | True %(ga_Bool)%

. And False x = False

. And True x = x

. And False True = False

### Hint 3.6, not a kind '? Bool'