Legal Case Retrieval (LCR) identifies relevant precedent cases to support legal reasoning and sentencing. A core challenge for cross-system LCR is the structural divergence between legal systems: civil-law systems provide explicit statutory hierarchies but lack inter-case citations, while common-law systems offer rich citation networks but lack uniform codified semantic hierarchies. Existing methods exploit only one side of this divide, remaining system-specific. We propose DSLaw, which unifies both systems by implicitly modeling hierarchical semantics through residual quantization and using the resulting discrete representations as semantic anchors for cross-case graph reasoning. By progressively decomposing legal semantics from coarse concepts to fine-grained distinctions, DSLaw constructs implicit connections even without explicit citations. Experiments on COLIEE2025 (common law) and ELAM (civil law) show DSLaw consistently outperforms strong baselines, while joint training further validates cross-system generalization. The implementation is provided at https://github.com/KDEGroup/DSLaw.

Prior representative ReAct-style approaches in autonomous Software Engineering (SWE) typically lack the explicit System-2 reasoning required for deep analysis and handling complex edge cases. While recent reasoning models demonstrate the potential of extended Chain-of-Thought (CoT), applying them to the multi-turn SWE task creates a fundamental dilemma: retaining full reasoning history leads to context explosion and “Lost-in-the-Middle” degradation, while discarding it would force the agent to redundantly re-reason at every step. To address these challenges, we propose SWE-AGILE, a novel software agent framework designed to bridge the gap between reasoning depth, efficiency, and context constraints. SWE-AGILE introduces a Dynamic Reasoning Context strategy, maintaining a “sliding window” of detailed reasoning for immediate continuity to prevent redundant re-analyzing, while compressing historical reasoning content into concise Reasoning Digests. Empirically, SWE-AGILE sets a new standard for 7B-8B models on SWE-Bench-Verified using only 2.2k trajectories and 896 tasks. Code is available at https://github.com/KDEGroup/SWE-AGILE.