LLMs increasingly use external tools and stateful environments for complex, multi-step tasks. Further improving their tool-use capabilities, however, remains bottlenecked by the lack of scalable stateful environments and verified multi-turn trajectories matched to the target LLM’s current capability boundary. We observe that agent skills, packages pairing workflow specifications with executable scripts, provide scalable seed material for tool-use environment synthesis. This motivates Grafting, a skill-to-environment synthesis loop in which coding-agent harnesses perform open-ended construction under deterministic validation contracts, producing self-contained executable environments that are refined using trajectory-level verdicts. In an initial end-to-end run, Grafting produces 500 environments and approximately 12K verified multi-turn trajectories. We train on these trajectories with Fathoming, an iterative GRPO procedure that selects verified trajectories near the target model’s capability boundary. Training a 4B-parameter instruction-tuned model with two rounds of Fathoming on the trajectory pool produces Fathom-4B and yields strong out-of-distribution gains: BFCLv4 multi-turn accuracy rises from 22.0 to 39.7 (+17.7 points), and ComplexFuncBench per-call accuracy rises from 49.6 to 61.6 (+12.0 points). Using the same environment-synthesis pipeline, we further construct Grove-5K, a collection of 5,101 executable environments. We release Grafting, Grove-500, Grove-5K, and Fathom-12K.

While reinforcement learning with verifiable rewards (RLVR) has advanced multimodal reasoning, coarse outcome rewards offer limited guidance for assigning credit to visual evidence. Analyzing same-prompt rollout groups, we observe that different outcomes exhibit distinct temporal patterns of measured visual dependency across reasoning segments. We therefore propose **VIGOR** (**Vi**sual **G**rounding **O**utcome-contrastive **R**einforcement), a policy optimization method that converts these group-wise contrasts into fine-grained supervision. VIGOR constructs outcome-conditioned prototypes from temporal visual fingerprints to reweight trajectories, uses segment-level contrasts to prioritize token gradients, and allocates the visual budget according to group difficulty. It requires no additional annotations or reward models and introduces no inference-time overhead. Across eight multimodal reasoning benchmarks, VIGOR achieves 57.5% average accuracy with Qwen2.5-VL-7B, improving over VPPO by 1.6 points. Controlled experiments further validate VIGOR on Qwen2.5-VL-3B and InternVL2.5-4B; on the latter, it outperforms VPPO on all eight tasks by 0.96 points on average. Our code is publicly available at https://github.com/beck83879-bit/VIGOR.

Aspect-based sentiment analysis (ABSA) predicts sentiment polarity towards a specific aspect in the given sentence. While pre-trained language models such as BERT have achieved great success, incorporating dynamic semantic changes into ABSA remains challenging. To this end, in this paper, we propose to address this problem by Dynamic Re-weighting BERT (DR-BERT), a novel method designed to learn dynamic aspect-oriented semantics for ABSA. Specifically, we first take the Stack-BERT layers as a primary encoder to grasp the overall semantic of the sentence and then fine-tune it by incorporating a lightweight Dynamic Re-weighting Adapter (DRA). Note that the DRA can pay close attention to a small region of the sentences at each step and re-weigh the vitally important words for better aspect-aware sentiment understanding. Finally, experimental results on three benchmark datasets demonstrate the effectiveness and the rationality of our proposed model and provide good interpretable insights for future semantic modeling.