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Questions tagged [equivalence]

Equivalence is a relationship in which two or more identifiers are abstractions for the same data structure.

References

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IP address v4/v6 equivalence testing

Is it possible to test IP addresses for equivalence in a dual stack environment using both IPv4 and IPv6? If so, how? My application uses websocket++ on top of Boost ASIO. As an example, on my LAN, one application connects to another listening on…
user1382306
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Using an equivalence in the context to force reduction

The setting for this question is the same "merge of sorted lists" example from this earlier question. {-# OPTIONS --sized-types #-} open import Relation.Binary open import Relation.Binary.PropositionalEquality as P hiding (trans) module…
Roly
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In Python, can you find a substring using a for loop and equivalence (==) ? No regex

Here is my problem: Write a program that takes two lines of input, we call the first needle and the second haystack. Print the number of times that needle occurs as a substring of haystack. I am encouraged to use a loop and the equivalence…
TIm Richardson
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How to calculate the decomposition A=P[I_r,0;0,0]Q in Python?

Given matrix A, is it possible to conveniently get the invertible matrices P and Q that appear in the matrix equivalence and satisfy A=P[I_r,0;0,0]Q with numpy or scipy?
Ziyuan
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Doesnt stl sort require a strict weak ordering to work?

From http://stdcxx.apache.org/doc/stdlibref/less-equal.html -- You can pass a less_equal object to any algorithm that requires a binary function. For example, the sort() algorithm can accept a binary function as an alternate comparison object to…
san
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Agda: Equivalence relation for sub-colists

I would like to define an equality on CoList (Maybe Nat)s that only takes the justs into account. Of course, I can't just go from CoList (Maybe A) to CoList A, because that wouldn't necessarily be productive. My question, then, is how could I define…
Cactus
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Finding Myhill-Nerode relation to get equivalence classes

Fix strings x and y, |x| < |y| = n. For any 2 strings of different lengths, there is a DFA with O(logn) states that accept x and rejects y. Prove that this DFA exists. My approach: I tried to find such a DFA and one obv one is with 2n states that…
Charlie
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How to check if multiple columns are row-wise equivalent, ignoring NA values

How can I check that: within a row all the values in certain columns are equal, while treating NA as missing data to be ignored? The special case of a row containing exclusively NA should return NA library(dplyr) library(tibble) dat <- tribble( …
mac
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Fortran EQUIVALENCE statement with array length from subroutine input

I'm modernizing some old Fortran code and I cannot get rid of an equivalence statement somewhere (long story short: it's mixed use is so convoluted it'd take too much work to convert everything). I need the length of the EQUIVALENCEd arrays to…
Federico Perini
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How to tell Prolog that two literals are equivalent

Anyone knows how to tell Prolog that n(n(p)) and n(p) represent the same thing? Or how to reduce n(n(p)) to n(p)?
theSongbird
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Haskell: Understanding do notation with if-else statements

I have the following code for an API for manipulating a robot: data Direction = Left | Right forward :: IO () blocked :: IO Bool turn :: Direction -> IO () I am trying to understand two programs that will move the robot forward unless it…
ceno980
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How to check for differences between two spaCy Doc objects?

I have two lists of the same strings each, except for slight variations in the strings of the second list, i.e. no capitalization, spelling errors, etc. I want to check whether or not spaCy does anything differently between the two strings. This…
Smogshaik
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Converting VBScript's Eqv Operator

If you google for PowerShell Eqv you currently will find the VBScript-to-Windows PowerShell Conversion Guide on top of the list. Yet the answer is much of technical help: Eqv Operator Definition: Performs a logical equivalence on two expressions. No…
iRon
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FORTRAN EQUIVALENCE in C++ language

I am converting a part of FORTRAN 77 code to C++ DIMENSION ARRAY(513),JRRAY(2,513) EQUIVALENCE (ARRAY(1),JRRAY(1,1)) This is implicit code where every variable name starting with I,J,K,L,M,N,O,P are implicitly taken as integer type. Thus, here we…
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Determining object equivalence using hash code

Let's say I have a simple class that represents a game tile, called Tile: public class Tile { public final int x; public final int y; public final int plane; public Tile(int x, int y, int plane) { this.x = x; this.y…
Martin Tuskevicius
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