Apple is about to fight the European Commission's claims that it must pay the €13 billion in back taxes ($13.6 billion) it allegedly owes from its deal with Ireland. The American firm tells Reuters that it's planning to appeal the ruling this week on the grounds that it not only can't abide by the decision, but that the figures don't make sense. To start, Apple argues that the EC falsely determined that two of its business units existed solely on paper, and thus didn't justify their untaxed profits. They were real, actively managed companies, the company claims. Also, Apple reportedly can't comply with the decision without making Ireland violate past tax laws that had different rules for residents and non-residents.