News for hackers. Stuff that matters.

A comment on King – Man + Woman = King?. Parent comment

Re:King – Man + Woman = King? by pure-awesome on Tuesday July 16, 2019 @05:58AM (#20448728)
Subtraction is not associative. One cannot just move parentheses around like that with numbers either:

5 - (2 + 3) =/= (5 - 2) + 3

The same holds for elements of a vector space.

[ Parent | on HN ]
Re:King – Man + Woman = King? by raverbashing on Tuesday July 16, 2019 @06:16AM (#20448793)
You are correct

I was about to say you were wrong, but you are correct, and it is a bit unintuitive why - https://www.quora.com/Is-vector-subtraction-associative

[ Parent | on HN ]
Re:King – Man + Woman = King? by EForEndeavour on Tuesday July 16, 2019 @08:21AM (#20449349)
Maybe I'm missing the point here, but what's so unintuitive about subtraction (vector or scalar) not being associative? Counterexamples seem easy to find. For example, 1 - 1 - 1 is not the same as 1 - (1 - 1).
[ Parent | on HN ]