Title says it all. I just need to confirm that... X.__add__(y) <==> x+y ...doesn't mean anything more than just 'same as'

The problem is Google returns zero results when you search for <==>

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    $\begingroup$ Can you at least provide a link to a page which uses this notation? $\endgroup$ – Andrej Bauer Jul 19 '16 at 6:34
  • $\begingroup$ <===> is not standard notation, so it is impossible to tell. Use your common sense. $\endgroup$ – Yuval Filmus Jul 19 '16 at 6:45
  • $\begingroup$ It's hard to tell without context; please give a link to where you found this. $\endgroup$ – Raphael Jul 19 '16 at 10:09
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    $\begingroup$ This is probably an attempt to write "$\iff$" using ASCII symbols. It means "if and only if" in the sense of formal logics, that is "$A \iff B$" translates to "whenever $A$ is true, then $B$ is well, and vice cersa". It seems to have been misused there, though. You don't give a source, but they seems to be wanting to express either "define X.__add__(y) to mean x+y" or "X.__add__(y) is equivalent to x+y". The latter seems to match the logical operator on a superficial, English-language level, but they equivalent things are not truth values here. $\endgroup$ – Raphael Jul 19 '16 at 10:09

Yes, it means "logically equivalent to".


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