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<p>Le 13/04/2019 à 14:29, Joachim Durchholz cites Richard O'Keefe :<br>
</p>
<blockquote type="cite"
cite="mid:f90d3799-e811-8bd3-aee4-7635b9cb1fbf@durchholz.org">
<blockquote type="cite">I would
<br>
be astonished if you had been told that
<br>
a ** b ** c
<br>
was defined to be
<br>
a ** (b ** c)
<br>
back in 1950-something,
<br>
</blockquote>
<br>
Actually we were told, with the reasoning that (a ** b) ** c is
the same as a ** (b * c), I recall that that was presented as
"nothing new there so not worth defining it that way).
<br>
<br>
Truth be told, that was the 1970-something for me.
<br>
</blockquote>
<p>'70?? Even worse...</p>
<p>I began my school in '50-something, and I was duly taught that.
And without "nothing new here", which I find rather unpleasantly
surprising. My teacher pointed out that (a**b)**c is equal to
a**(b*c), so the left associativity would not be extremely clever.
<br>
</p>
<p>Joachim says in his previous posting:</p>
<p>
<blockquote type="cite">I guess my intuition is more based on
math, where associativity is an irrelevant detail</blockquote>
Now, this is for me a <b>REALLY</b> peculiar vision of math.
Irrelevant detail?? Where? In the categorical calculus perhaps?
Abandon the associativity of morphisms, and you will see...</p>
<p> In Lie algebras maybe? Well, add the associativity to it, and
kill all the quantum theory.<br>
</p>
<p>Good luck.</p>
<p>There are many people, mainly young (e.g. my students) who have a
tendency to "see mathematics" through "computer lenses" - parsing,
implementable data structures, recursion as an implementation
detail, etc. For the mathematical culture this is harmful.<br>
</p>
<p>Jerzy Karczmarczuk</p>
<p><br>
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