There is accidental duplication to beware of. That is when different things looks the same. Then there is real duplication.. Only the later is bad and should be eliminated. Telling the differences is hard

I'd rather look at a simple arithmaticl expression and know immediately what is going on, rather than have to make up a hard to remember name for every small expression that happens to get repeated one or more times in the name of DRY. The same applies to small bits of non-arithmatical code.