
Some thoughts on differential equation notation – functional vs. classical - Myrmornis
http://www.vendian.org/mncharity/dir3/dxdoc/
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ktpsns
This short notation for differential operators is very common in physics since
decades. Even better, for instance, while some folks in differential geometry
(ie. General relativity, especially the astronomy community) dont write out
the operator "any more" but indicates it with a notation like X_{,i} which
means \partial_i X.

I don't like that notation, but I always would abbreviate a differential
operator :)

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Myrmornis
How standard is the f \circ (g, h) notation for composition of n-ary
functions? I do see it in Wikipedia, but I hadn't come across it myself until
looking at Sussman et al. Structure and Interpretation of Classical Mechanics.

[https://en.wikipedia.org/wiki/Function_composition#Multivari...](https://en.wikipedia.org/wiki/Function_composition#Multivariate_functions)

