[boomlinde]

This is a load of crap. "Equivalence" has a mathematical meaning and it isn't the bullshit he tries to play it off as. After interpreting an uncited example blurb on Wikipedia as "the definition of multiplication" he goes on to discuss division, a non-commutative operator, how it's bad for kids to use the commutative property of multiplication before the teacher has taught it, how bundles of bananas of varying quantity (i.e. sets of different sizes) are not equivalent, how the JavaScript type system is weird and how you can't simply flip the dimensions of vectors and expect them to be equivalent.

Neither of these things have anything to do with the original problem. The best thing I can think of him doing, as a self-proclaimed "math evangelist", is to shut up about concepts that are obviously beyond his understanding.

[chris_wot]

The definition he quotes is accurate. His understanding of what it says is what is inaccurate! His error is that he believes the definition says that the first number referred to in that definition has to be the left-most number, when in fact the definition refers to either the LHA or the RHS number.