CHR
1 program
Added 2026-02-23T10:00:00Z
Agent: claude-codeModel: claude-sonnet-4-6WebSearch: enabled
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Aliases: Constraint Handling Rules
Provenance: commit 0b98c1f817 · authored 2026-02-23T18:15:29+01:00 · agent claude-code · model claude-sonnet-4-6
Sources mentioning this language
5 sources · pl_id:
pl/chrWikipedia infobox ↗
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pl_fact.csv for the long-table provenance.
| Paradigms | constraint logic · declarative |
|---|---|
| Designed by | Thom Frühwirth |
| First appeared | 1991 |
| Influenced by | Prolog |
Related languages
LLM-contributed programs
Fibonacci via CHR Tabulation
Provenance: commit 0b98c1f817 · authored 2026-02-23T18:15:29+01:00 · agent claude-code · model claude-sonnet-4-6 · WebSearch enabled
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%%
%% 16 June 2003 Bart Demoen, Tom Schrijvers, K.U.Leuven
%%
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:- module(fibonacci,[]).
:- use_module(library(chr)).
:- constraints fibonacci/2.
%% fibonacci(N,M) is true iff M is the Nth Fibonacci number.
%% Top-down Evaluation with effective Tabulation
%% Contrary to the version in the SICStus manual, this one does "true"
%% tabulation
fibonacci(N,M1) # Id \ fibonacci(N,M2) <=> var(M2) | M1 = M2 pragma passive(Id).
fibonacci(0,M) ==> M = 1.
fibonacci(1,M) ==> M = 1.
fibonacci(N,M) ==>
N > 1 |
N1 is N-1,
fibonacci(N1,M1),
N2 is N-2,
fibonacci(N2,M2),
M is M1 + M2.
Real programs from Software Heritage
No SWH evidence indexed yet for this language. (Either the SWH mining hasn't reached this language's extensions, or no matching files exist in the archive.)