The House of David

"dawnbreak in the west"

Thursday, June 23, 2016

Associative pairing symbols should be symmetric

Two years ago, the "equality" meme started up, with "marriage equality" being the big buzzword. The social-justice entrepreneurs sent out a lot of purple squares with yellow equal-signs (=) on them; they were on lots of cars, especially on models worth more than my car. Not so much now, but they were there then. Some of us dissident-righters were thinking of posting UNequal-signs (≠). The guy who thought that up didn't get the angle right on the crossout, so the idea had to go through a bit of a "Q A" process first. But now I'm wondering - why should it matter?

Math symbols are those in which A * B means "A [blah] B". To take arithmetic as an example, A + B is the same as B + A, and A x B = B x A. Such relations are called associative. The "Greater Than" / "Less Than" pair is different; A > B is clearly opposite from A < B. It matters what side of what symbol you're on.

You'll note that the plus (+) symbol here hints at associativity in that it is symmetric across the vertical axis. The equal symbol is similar. "Greater Than" / "Less Than" hints at non-associativity.

It'd be nice if the mathematicians had thought of this when they developed the minus sign (-). It's not associative. Neither is the divide sign, but I don't think anyone even uses that anymore; for my part since getting into computers I've always used the fraction sign (/).

Anyway, the not-equal sign represents one of the associative processes: if A ≠ B, then B ≠ A. The symbol should be symmetric and, failing that, it shouldn't matter where the strikethrough leans.


posted by Zimri on 17:19 | link | 0 comments

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