anchor.diff:         ("let A = id ( true , false ) in (|| A) = true" :swe "let A = id ( true , false ) in (|| A) = true" :value '(:|Bool| . t))
          ("(|| ( true , true )) = true" :swe "(|| ( true , true )) = true" :value '(:|Bool| . t))
          ("let A = id ( true , true ) in (|| A) = true" :swe "let A = id ( true , true ) in (|| A) = true" :value '(:|Bool| . t))
  -       ("[(||)(true,true)] = [(||)(true,true)]"     :swe "[(||)(true,true)] = [(||)(true,true)]"     :value '(:|Bool| . t))
  +       ("[(||)(true,true)] = [(||)(true,true)]"     :swe "[(||)(true,true)] = [(||)(true,true)]" :value '(:|Bool| . t))
          ;; Boolean [  4]:  op =>  infixr 13 : Boolean * Boolean -> Boolean 
          ("(=> ( false , false )) = true" :swe "(=> ( false , false )) = true" :value '(:|Bool| . t))
          ("let A = id ( false , false ) in (=> A) = true" :swe "let A = id ( false , false ) in (=> A) = true" :value '(:|Bool| . t))
  
positive.code:        ("let A = id ( true , false ) in (&& A) = false" :swe "let A = id ( true , false ) in (&& A) = false" :value '(:|Bool| . t))
         ("(&& ( true , true )) = true" :swe "(&& ( true , true )) = true" :value '(:|Bool| . t))
         ("let A = id ( true , true ) in (&& A) = true" :swe "let A = id ( true , true ) in (&& A) = true" :value '(:|Bool| . t))
         ("[(&&)(true,true)] = [(&&)(true,true)]"     :swe "[(&&)(true,true)] = [(&&)(true,true)]"     :value '(:|Bool| . t))
         ;; Boolean [  3]:  op ||  infixr 14 : Boolean * Boolean -> Boolean 
         ("(|| ( false , false )) = false" :swe "(|| ( false , false )) = false" :value '(:|Bool| . t))
         ("let A = id ( false , false ) in (|| A) = false" :swe "let A = id ( false , false ) in (|| A) = false" :value '(:|Bool| . t))
  
negative.code:        ("let A = id ( true , false ) in (=> A) = false" :swe "let A = id ( true , false ) in (=> A) = false" :value '(:|Bool| . t))
         ("(=> ( true , true )) = true" :swe "(=> ( true , true )) = true" :value '(:|Bool| . t))
         ("let A = id ( true , true ) in (=> A) = true" :swe "let A = id ( true , true ) in (=> A) = true" :value '(:|Bool| . t))
         ("[(=>)(true,true)] = [(=>)(true,true)]"     :swe "[(=>)(true,true)] = [(=>)(true,true)]" :value '(:|Bool| . t))
         ;; Boolean [  5]:  op <=> infixr 12 : Boolean * Boolean -> Boolean 
         ("(<=> ( false , false )) = true" :swe "(<=> ( false , false )) = true" :value '(:|Bool| . t))
         ("let A = id ( false , false ) in (<=> A) = true" :swe "let A = id ( false , false ) in (<=> A) = true" :value '(:|Bool| . t))
  