private String evalExpectedType2(ArrayList equiv, int n) throws BadBytecode {
            String origName = null;
            for (int i = 0; i < n; i++) {
                TypeData td = (TypeData)equiv.get(i);
                if (!td.isNullType())
                    if (origName == null)
                        origName = td.getName();
                    else if (!origName.equals(td.getName()))
                        return null;
            }

            return origName;
        }