Just because you can't define something mathematically, doesn't mean it isn't obvious to most people in 99% of cases.
Reminds me of the endless games in tax law/avoidance/evasion and the almost pointless attempt to define something absolutely in words. To be honest you could simplify the whole thing by having a 'taking the piss' test - if the jury thinks you are obviously 'taking the piss' then you are guilty - and if you whine about the law not being clear and how it's unfair because you don't know whether or not you are breaking the law - well don't take the piss then - don't pretend you don't know whether something is an agressive tax dodge or not.
If you create some fake IP, and license it from some shell company in a low tax regime to nuke your profits in the country you are actually doing business in - let's not pretend we all can't see what you doing there - you are taking the piss.
Same goes for what some tech companies are doing right now - every reasonable person can see they are taking the piss - and high paid lawyers arguing technicalities isn't going to change that.