Towards General Loop Invariant Generation via Coordinating Symbolic Execution and Large Language Models

Loop invariants, essential for program verification, are challenging to auto-generate especially for programs incorporating complex memory manipulations. Existing approaches for generating loop invariants rely on fixed sets or templates, hampering adaptability to real-world programs. Recent efforts have explored machine learning for loop invariant generation, but the lack of labeled data and the need for efficient generation are still troublesome. We consider the advent of the large language model (LLM) presents a promising solution, which can analyze the separation logic assertions after symbolic execution to infer loop invariants. To overcome the data scarcity issue, we propose a self-supervised learning paradigm to fine-tune LLM, using the split-and-reassembly of predicates to create an auxiliary task and generate rich synthetic data for offline training. Meanwhile, the proposed interactive system between LLM and traditional verification tools provides an efficient online querying process for unseen programs. Our framework can readily extend to new data structures or multi-loop programs since our framework only needs the definitions of different separation logic predicates, aiming to bridge the gap between existing capabilities and requirements of loop invariant generation in practical scenarios. Experiments across diverse memory-manipulated programs have demonstrated the performance of our proposed method compared to the baselines with respect to efficiency and effectiveness.Comment: Preprint, under revie

The impact of ‘seasonal urban event’ to the hosting city’s urban vitality: case study of Summer beach and Winter Wonderland in Nottingham, UK

Hosting seasonal urban events in open public spaces has a significant impact on urban vitality. By reviewing the categorisation of urban events, this paper explains the charactersitics of ‘Seasonal Urban Event’ through time, scale, location, format, content, function, and aim. It mainly focuses on leisure and entertainment events through two cases, Summer Beach and Winter Wonderland at Old Market Square in Nottingham, UK. The research explores ‘Seasonal Urban Event’ by literature review, open data, observation, and the survey data analysis of participants’ responses. The survey result indicates positive spatial and social engagement levels ranging from accessibility, legibility, permeability, flexibility to participation, satisfaction, and inclusivity. The potential benefits of social impact have been emphasised by participants’ responses to elevating civic pride and improving the level of social inclusion. It concludes that ‘Seasonal Urban Event’, as a useful supplement method, may enhance urban vitality in the hosting city

miR-379 deletion ameliorates features of diabetic kidney disease by enhancing adaptive mitophagy via FIS1

Diabetic kidney disease (DKD) is a major complication of diabetes. Expression of members of the microRNA (miRNA) miR-379 cluster is increased in DKD. miR-379, the most upstream 5′-miRNA in the cluster, functions in endoplasmic reticulum (ER) stress by targeting EDEM3. However, the in vivo functions of miR-379 remain unclear. We created miR-379 knockout (KO) mice using CRISPR-Cas9 nickase and dual guide RNA technique and characterized their phenotype in diabetes. We screened for miR-379 targets in renal mesangial cells from WT vs. miR-379KO mice using AGO2-immunopreciptation and CLASH (cross-linking, ligation, sequencing hybrids) and identified the redox protein thioredoxin and mitochondrial fission-1 protein. miR-379KO mice were protected from features of DKD as well as body weight loss associated with mitochondrial dysfunction, ER- and oxidative stress. These results reveal a role for miR-379 in DKD and metabolic processes via reducing adaptive mitophagy. Strategies targeting miR-379 could offer therapeutic options for DKD

Influence of End Effect on Rock Strength in True Triaxial Compression Test

The influence of the end effect on rock strength in true triaxial compression test was studied using a numerical approach. The influence of σ2 on rock strength was isolated by using the 2D Mohr-Coulomb failure criterion that depends only on σ1 and σ3. Thus, any enhancement to rock strength with the increase of σ2 can be attributed to the end effect. It was shown that the end effect can result in an apparent σ2 effect, as long as the coefficient of friction (μ) at rock specimen-steel platen contacts is not zero and the specimen in the σ2 loading direction is squat. When the strengthening due to the increase of σ2 predicted by a theoretical failure criterion was added to the strengthening due to the end effect, the results were in good agreement with the observed σ2 effect from some previous laboratory tests, indicating that the observed σ2 effect in true triaxial compression test could be partially influenced by the end effect, particularly when σ3 was low. It is suggested to decrease the end effect to a level where the apparent σ2 effect is very small so that the obtained test results are more meaningful to characterize the actual σ2 effect.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author