Correct deriving True to be a data constructor, not variable.
Corrected transformation of type synonym definition. Need to create synonym for type that is neither function nor expandable type synonym.
Corrected bug that deriving of Ord actually generated deriving of Eq.
Corrected bug in know-arity call of worker function and superfluous argument for trusted if-combinator.
Corrected transformation of unary - (negation).
Removed buggy desugaring of list-comprehensions to filter and foldr; instead desugar to do-expression.