16 questions linked to/from How is pattern specificity decided?
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### Precedence of defined functions [duplicate]

When I define functions in Mathematica like: f[x_] := 3 f[x_Integer] := 6 How is the value of f determined? It seems to ...
999 views

### How can one manually change the rule ordering

I have a function which has some general behavior, but that should act on some specific kinds of objects in some other way. I know that Mathematica is supposed to automatically order the rules so that ...
2k views

### A function that accepts a pair or a list of pairs

Probably a duplicate, but it's not easy to search on "lists". I have a function that accepts a list of lists, say {{a1, b1}, {a2, b2}, {a3, b3}} and performs some ...
2k views

### How to generally match, unify and merge patterns?

This question was split from this one. While that question is now about how to match two particular patterns (mostly using Verbatim or ...
833 views

### When is a symbol a Symbol? Is there an easy Mathematica way to test if an object is a symbol sort of like a SymbolQ?

Yes I know there is no built-in native function called SymbolQ (but JavaScript does). However, could one be simulated to work for most cases? I often rely on ...
389 views

### Is there a defined priority for pattern matching?

If you define a function g, like so: g[x_?EvenQ] := "even" g[x_?NumberQ] := "number" why will Mathematica always return ...
284 views

### Making strict replacements in Mathematica

My question is quite a simple one, but I have not been able to find a solution yet. Say I have terms of the form e.g 1/n1/n2/n3/n4 and ...
227 views

### What makes a pattern more general?

This is a rewording of the question. The original post is below. How come that a pattern for an expression with a specific head is not more specific than a pattern for an expression with a generic ...
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### Which function definition is used to evaluate an expression that matches the lefthand side of more than one definition?

In a case like this: f[a_] := a; f[{a_, b_}] := a; I'm wondering whether I should expect f[{2, 3}] to return ...
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### Counterintuitive DownValue precedence

Consider the following definitions for two symbols: foo[a] /; True := b foo[a] := a foo[a] (* a *) foo2[a_] /; True := b foo2[a_] := a foo2[a] (* b *) (The ...
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### Sorting a list of rules

When we give several definitions for a function f, the DownValues of f are automatically ...
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### On the order of rules specification [duplicate]

I wanted to understand how Mathematica parses function definitions in rules-based programming, so I started with the simple code: ...
112 views

### Upvalues and order of interpretation

I'm trying to use UpValues to improve the usability of some code, but I am running into an issue where the order of the UpValues is important, and I am not sure if it is my understanding or a ...