Questions related to handling built-in symbols, for example why they behave a certain (possibly unexpected) way.

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7
votes
1answer
207 views

Defining my own invisible operator

There are some invisible operators in Mathematica (\[ImplicitPlus],\[InvisibleTimes],...
1
vote
0answers
56 views

Define an operator without Built-in Meanings containing a Power function [duplicate]

I would like to define the following operator: $$ \left[T^{(j_{1})}\otimes U^{(j_{2})}\right]_{m}^{(j)}=\sum_{m_{1},m_{2}}\left\langle j_{1},m_{1};j_{2},m_{2}\big|j,m\right\rangle ...
6
votes
2answers
272 views

No builtin function for bitwise rotation?

There appears to be no builtin Mathematica function for bitwise rotation. Is that true? I suppose I can write my function: ...
8
votes
4answers
378 views

When should I use Apply (or Function) and when @@ (or &)?

This is a rather general question, which I fail to answer myself. I guess it is mainly due to my insufficient knowledge of the precise terms. If I understand correctly, the following are equivalent: ...
2
votes
2answers
114 views

How to unprotect GeneratingFunction

I'm trying to add custom downvalues for GeneratingFunction, and to do so I thought I just had to Unprotect it. However, that ...
7
votes
1answer
132 views

Builder pattern for complex objects construction

Intro I was watching "UnRisk-Q Instrument Builder" talk (https://www.youtube.com/watch?v=Xx3goIBpOdE) and those guys use builder pattern to build complex objects like this: ...
9
votes
1answer
117 views

Why are some option values symbols, other strings?

Is there a rationale, beyond historical accident, why some Mathematica option values are strings, while others are symbols? It seems natural that some value spaces, e.g. named color schemes, are so ...
5
votes
1answer
372 views

Using the symbol I for electrical current [duplicate]

I would like to use the I as a symbol for the electrical current. How can I redefine it, so it is not interpreted as the imaginary unity?
8
votes
2answers
161 views

Replacing product expressions - named vs. unnamed pattern?

Suppose I have an expression of the form a b c d + x y z The FullForm of this is ...