finding

active

finding:llama-3-1-8b-reuses-a-single-generic-addition-mechanism-across-all-cyclic-tasks-independently-of-concept-specific-geometry

Llama-3.1-8B reuses a single generic addition mechanism across all cyclic tasks independently of concept-specific geometry

Key mechanistic finding showing task-agnostic reuse of arithmetic circuitry

Source paper

extracted_from

Arithmetic in the Wild: Llama uses Base-10 Addition to Reason About Cyclic Concepts

(2026) · Sheridan Feucht · Tal Haklay · Usha Bhalla · Daniel Wurgaft +8

Neighborhood — ranked by edge-count

Claims (2)

claim

Circular representational structure does not imply that the model computes using the corresponding modular arithmetic
supports
The paper's primary interpretive claim, directly answering the central question
Language models prefer reusing generic arithmetic mechanisms over learning task-specific modular computations even when task-specific geometry exists
supports
Broader interpretive claim about LM learning bias inferred from the findings

Hypotheses (1)

hypothesis

We hypothesize that Llama-3.1-8B deploys the same base-10 addition circuitry for cyclic reasoning as it uses for general arithmetic, independent of the concept domain
associated_with
Predictive hypothesis about domain-generality of the identified mechanism

Related by similarity (8)

cosine ≥ 0.65 · no typed edge

Entities in the same semantic neighborhood but without a typed relation to this one — candidates for new edges or unrecognized duplicates.

Llama-3.1-8B uses base-10 addition rather than modular addition to compute cyclic concept sumsfinding0.858
The central empirical finding that computation does not mirror the circular representational structure
Does Llama compute modular addition or base-10 addition for cyclic tasks?question0.839
The specific computational question the paper resolves empirically
Llama-3.1-8B implements a two-stage algorithm: (1) compute integer sum via base-10 addition (e.g., six + August = 14), then (2) map sum to cyclic concept space (14 → February)finding0.827
The complete mechanistic algorithm discovered for cyclic concept reasoning
How does Llama-3.1-8B reason over cyclic concepts?question0.825
The empirical question the paper addresses through mechanistic investigation
An addition module in layer 18 of Llama-3.1 8B performs arithmetic using circular geometric representations of numbers.quote0.818
Verbatim summary of the main discovery.
Llama-3.1-8B representations for cyclic concepts are circularly structuredfinding0.811
The representation geometry finding that motivates the question about whether computation mirrors it
Llama-3.3-70B exhibits internal consistency-checking mechanisms that operate during inferenceclaim0.805
Central interpretive claim of the paper supported by causal ablation and activation evidence
Llama-3.1-8B uses task-agnostic Fourier features with periods 2, 5, and 10 (base-10) rather than concept-specific periods (e.g., 12 for months)finding0.804
The specific Fourier feature periods identified confirm base-10 rather than modular computation