anchor.diff:    | Error_UncontrainedUnificationVar
     | Error_UnexpectedGTotComputation
     | Error_UnexpectedInstance
  -  | Error_BadImplicit
     | Error_UnknownFatal_AssertionFailure
     | Error_Z3InvocationError
     | Error_IDEAssertionFailure
  
positive.code:   (Warning_Z3InvocationWarning                       , CWarning);
    (Warning_MissingInterfaceOrImplementation          , CWarning);
    (Warning_ConstructorBuildsUnexpectedType           , CWarning);
    (Warning_ModuleOrFileNotFoundWarning               , CWarning)]
  
  exception Err of raw_error* string
  exception Error of raw_error * string * Range.range
  
negative.code:   (Error_UncontrainedUnificationVar                  , CError);
    (Error_UnexpectedGTotComputation                   , CError);
    (Error_UnexpectedInstance                          , CError);
    (Error_UnknownFatal_AssertionFailure               , CError);
    (Error_Z3InvocationError                           , CError);
    (Error_IDEAssertionFailure                         , CError);
  