Large-scale verifiable prompts underpin the success of Reinforcement Learning with Verifiable Rewards (RLVR), but they contain many uninformative examples and are costly to expand further. Recent studies focus on better exploiting limited training data by prioritizing hard prompts whose rollout pass rate is 0. However, easy prompts with a pass rate of 1 also become increasingly prevalent as training progresses, thereby reducing the effective data size. To mitigate this, we propose Composition-RL, an offline data-augmentation approach that composes existing prompts before RL to address the pass-rate-1 bottleneck without modifying the RL optimizer. The composed dataset is generated and verified once from the fixed source pool and then used for RL training. Extensive experiments across model sizes from 4B to 30B show that Composition-RL consistently improves reasoning capability over RL trained on the original dataset. Performance can be further boosted with a curriculum variant of Composition-RL that gradually increases compositional depth over training. Additionally, Composition-RL enables more effective cross-domain RL by composing prompts drawn from different domains. All our code, data, and models are publicly available to facilitate future research.
Figures & tables
Figure 1: Overview of Composition-RL . Top: an example of composing two math problems, illustrating the high-level idea of Composition-RL . Bottom left: pass@1 (%) on AIME24 versus training steps, summarizing key findings in Sections 5.2 and 5.3 . Bottom right: cross-topic results on MMLU-Pro subjects with the top-5 largest sample sizes, highlighting the main finding in Section 5.4 .
Figure 2: Visualization of meta-experiments. Left: solve_all ratio curve for RL of Qwen3-4B-Base with original prompts (MATH12K) versus compositional prompts. Right: avg@8 accuracy on a subset of MATH500 and its corresponding compositional test prompts.
Method / Data
Mathematics (In-Domain)
Multi-Task (Out-Of-Domain)
Overall
AIME 24
AIME 25
Beyond AIME
IMOBench
Overall
GPQA
MMLU-Pro
Overall
Overall
Avg@32
Avg@32
Avg@8
Avg@4
Avg.
Avg@8
Avg@1
Avg.
Avg.
Qwen3-4B-Base
GRPO
23.3
19.5
9.0
14.4
16.6
43.7
58.6
51.2
28.1
MetaMath ∗
12.7
9.7
3.9
8.1
8.6
43.9
58.5
51.2
22.8
SAND-Math ∗
25.6
20.5
8.9
15.4
17.6
45.4
57.9
51.7
29.0
Table 1: Main Results. “ Avg@k ” denotes the average accuracy (%) over k random generations (i.e., pass@1 ). The rows “Depth 1 + 2” and “+ Depth 3” are the results of curriculum Composition-RL in Section 5.3 . ∗ indicates that the corresponding results are obtained using the same training set size as MATH12K. For Composition-RL , the starred row uses a 12K subset of MATH-Composition-199K , while the unstarred row uses the full set.
Dataset
Mathematics
Multi-Task
Overall
AIME 24
AIME 25
Beyond AIME
IMOBench
Overall
GPQA
MMLU-Pro
Overall
Overall
Avg@32
Avg@32
Avg@8
Avg@4
Avg.
Avg@8
Avg@1
Avg.
Avg.
MATH12K
23.3
19.5
9.0
14.4
16.6
43.7
58.6
51.2
28.1
MATH12K + Physics
19.7
16.5
8.3
12.0
14.1
44.4
59.6
52.0
26.8
Physics after MATH12K
25.3
22.3
8.6
14.4
17.7
45.2
61.4
53.3
29.5
Physics-MATH-Composition-141K
32.4
25.5
10.6
17.8
21.6
46.6
62.7
54.7
32.6
Table 2: Results of cross-topic experiments across multiple benchmarks. “ Avg@k ” denotes the average accuracy (%) over k random generations (i.e., pass@1 ). “ MATH12K + Physics ” corresponds to the Mix Training baseline, and “ Physics after MATH12K ” corresponds to the Math-then-Physics baseline. The final block uses 10K multidisciplinary prompts from SCP-116K [ 64 ] .
D1
D2
Mathematics (In-Domain)
Multi-Task (Out-Of-Domain)
Overall
AIME 24
AIME 25
Beyond AIME
IMOBench
Overall
GPQA
MMLU-Pro
Overall
Overall
Avg@32
Avg@32
Avg@8
Avg@4
Avg.
Avg@8
Avg@1
Avg.
Avg.
Baseline
23.3
19.5
9.0
14.4
16.6
43.7
58.6
51.2
28.1
RAND
RAND
22.6
19.6
8.2
13.8
16.1
43.6
60.0
51.8
28.0
FULL
RAND
24.5
23.4
8.7
14.1
17.7
44.8
59.9
52.4
29.2
RAND
FULL
30.5
23.3
12.6
14.3
20.2
46.3
61.4
53.9
31.4
Table 3: Results of the ablation study. D1 specifies the strategy for constructing the candidate set for q1 : “RAND” randomly samples 20 prompts, whereas “FULL” selects from the entire original prompt set D . “Baseline” denotes RL training on the original prompts D . “Direct Concat” denotes RL training on prompts that are directly concatenated from two prompts without composition. For results on the fully solvable subset, n is the number of rollouts. Additional blocks report the Feeding- v1 control, standalone training at each composition depth, and adaptive Depth-2 composition.
Figure 3: Left : avg@8 accuracy on Depth-3 compositional test prompts across different model sizes. The bars compare Original RL with Composition-RL, i.e., whether Depth-2 compositional prompts are used during RL training. Right : The fraction of prompts for which q1:2 is solved correctly, and the accuracy of recovering v1 at each training step.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 4: The Prompt for Verifying the Correctness of Finding v1 in LLMs’ Response.
Source difficulty
Composition
pass@1
pass@8
solve_all
solve_none
Informative
Easy → Easy
N
99.3
100.0
94.5
0.0
5.5
Easy → Easy
Y
89.2
98.6
69.9
1.4
28.8
Easy → Hard
N
66.3
78.3
51.7
21.7
26.7
Easy → Hard
Y
57.7
83.3
26.7
16.7
56.7
Hard → Easy
N
99.8
100.0
98.3
0.0
1.7
Hard → Easy
Y
68.5
93.1
34.5
6.9
58.6
Appendix
Table 4: Difficulty-stratified evaluation (%). “Informative” denotes prompts that are neither solve_all nor solve_none .
Step
At least one source
Both sources
is solve_all
are solve_all
50
84.8
36.4
100
91.2
48.7
200
95.7
62.1
250
97.3
69.0
Appendix
Table 5: Overlap of solve_all source prompts during training (%).
Metric (%)
Baseline
Ours
First-attempt correctness
42.8
51.7
P(correct∣reflection)
11.0
19.8
Self-correction success
9.1
26.1
Appendix
Table 6: Additional evidence of implicit process supervision on AIME24 with the 4B model.
Error Type
Original
Composition-RL
Linkage error
22
7
q1 error
7
1
q2 error
11
5
Appendix
Table 7: Error analysis on 40 cases where the model solves both constituent questions in isolation but fails on the compositional question.
Composition
Mathematics (In-Domain)
Multi-Task (Out-Of-Domain)
Overall
AIME 24
AIME 25
Beyond AIME
IMO-Answer
ID Avg
GPQA
MMLU-Pro
OOD Avg
Avg
Qwen3-4B-Base
✘
16.0
13.4
13.3
12.8
13.9
4.2
2.3
3.3
10.3
✔
14.7
13.2
12.3
12.9
13.3
4.0
2.0
3.0
9.9
Qwen3-8B-Base
✘
17.5
15.7
16.9
15.8
16.5
5.1
2.5
3.8
12.3
Appendix
Table 8: Average response length (in K tokens) across different benchmarks. “ID Avg” denotes the average response length over in-domain mathematics benchmarks, “OOD Avg” denotes the average response length over out-of-domain multi-task benchmarks, and “Avg” denotes the overall average.
Composition
Mathematics (In-Domain)
Multi-Task (Out-Of-Domain)
Overall
AIME 24
AIME 25
Beyond AIME
IMO-Answer
ID Avg
GPQA
MMLU-Pro
OOD Avg
Avg
Pass@32
Pass@32
Pass@8
Pass@4
Avg.
Pass@8
Pass@1
Avg.
Avg.
Qwen3-4B-Base
✘
56.7
46.7
23.0
25.5
38.0
79.3
58.6
69.0
48.3
✔
66.7
56.7
31.0
26.0
45.1
77.8
61.4
69.6
53.3
Qwen3-8B-Base
Appendix
Table 9: Pass@k (%) across different benchmarks. The value of k for each benchmark is consistent with that used in the corresponding Avg@k setting in the main results table. “ID Avg” denotes the average pass@k over in-domain mathematics benchmarks, “OOD Avg” denotes the average pass@k over out-of-domain multi-task benchmarks, and “Avg” denotes the overall average.
Benchmark
Baseline
Composition-RL
AIME24
1.58
1.65
AIME25
1.52
1.60
BeyondAIME
1.23
1.35
GPQA
1.08
1.14
IMOBench
1.27
1.33
MMLU-Pro
0.80
0.92
Appendix
Table 10: Standard deviation of pass@1 (percentage points) over three training seeds for Qwen3-30B-A3B-Base .
Benchmark
Baseline
Composition-RL
AIME24
3.44
5.94
AIME25
1.88
2.81
AMC
24.85
28.12
BeyondAIME
1.25
1.62
GPQA
25.88
29.23
IMO-Answer
5.31
5.44
Appendix
Table 11: pass@1 (%) with OctoThinker-3B .
Figure 5: solve_all and solve_none ratio across model sizes.
Figure 6: The Prompt for Generating Variable v1 and Definition d1 for q1 .
Figure 7: The Prompt for Verifying the Modification of q1 .