"1+1=3" is only incorrect in the standard accepted definition of arithmetic. That is inherently the subjective part. Nothing prevents people from using different math system. At the very least, I could say 1+1=10 in binary and you have to concede that you need to add more caveats to your statement. The other form of subjectivity is that style/performance/complexity is always considered for programming and the tradeoff is always subjective.