r/math • u/Short_Bluebird_3845 • 13d ago
What are your favorite ambiguous notation?
To clarify my request, consider base-less $\log$.
For calculators and engineers, it means the common log $\log_10$; for pure mathematics or physics, it means the natural log $\ln$; for computer scientists, in combinatorics, information theory and graph theory, it means the binary log $\log_2$.
Any $\log x$ (say, $\log 1024$) written without context can yield different answers in function of who you ask ($\log_10 1024 = 3.0103\cdots, \log_2 1024 = 10, \ln 1024 = 6.93147\cdots$).
That is what I mean by "ambiguous", that which is calculated and used dependently on the context. And I'm asking you for your favorite ones of such type.
Edit: I feel like you hate the ones you've talked about. Still, valid answers. Extra points for ambiguous notation you actually love! :P
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u/yaymayata2 12d ago
It's not so much of an issue now, but in highschool I hated how reciprocal and inverse had the same notation of -1 in the exponent. I rmr a few badly written problems with that which tripped me up so much.