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Discovering program specifications automatically for heap-manipulating programs is a challenging task due to the complexity of aliasing and mutability of data structures. This task is further complicated by an expressive domain that combines shape, numerical and bag information. In this paper, we propose a compositional analysis framework that would derive the summary for each method in the expressive abstract domain, independently from its callers. We propose a novel abstraction method with a bi-abduction technique in the combined domain to discover pre-/post-conditions that could not be automatically inferred before. The analysis does not only infer memory safety properties, but also finds relationships between pure and shape domains towards full functional correctness of programs. A prototype of the framework has been implemented and initial experiments have shown that our approach can discover interesting properties for non-trivial programs. [ABSTRACT FROM AUTHOR]

Abstract: Automatically verifying heap-manipulating programs is a challenging task, especially when dealing with complex data structures with strong invariants, such as sorted lists and AVL/red–black trees. The verification process can greatly benefit from human assistance through specification annotations, but this process requires intellectual effort from users and is error-prone. In this paper, we propose a new approach to program verification that allows users to provide only partial specification to methods. Our approach will then refine the given annotation into a more complete specification by discovering missing constraints. The discovered constraints may involve both numerical and multi-set properties that could be later confirmed or revised by users. We further augment our approach by requiring partial specification to be given only for primary methods. Specifications for loops and auxiliary methods can then be systematically discovered by our augmented mechanism, with the help of information propagated from the primary methods. Our work is aimed at verifying beyond shape properties, with the eventual goal of analysing full functional properties for pointer-based data structures. Initial experiments have confirmed that we can automatically refine partial specifications with non-trivial constraints, thus making it easier for users to handle specifications with richer properties. [Copyright &y& Elsevier]

[Display omitted] • Multiwalled carbon nanotube@poly(quinone-thiourea) (MWCNT@PQTU) composite was fabricated. • A core–sheath nanostructure of MWCNT@PQTU was formed. • Ultrathin PQTU layers with 10–30 nm in thickness were tightly adhered onto MWCNT. • MWCNT@PQTU exhibited a discharge capacity of 120.6 mAh/g at 100 mA g−1. Quinone-based redox active polymers are regarded as the most suitable cathode materials for constructing high-energy aqueous zinc-ion battery (AZIB) because of adjustable structure, high capacity and excellent electrochemical reversibility. However, their Zn2+ storage performances are often limited by low electronic conductivity and sluggish ion diffusion of Zn2+. Herein, a novel inorganic–organic nanocomposite of multiwalled carbon nanotube@poly(quinone-thiourea) (MWCNT@PQTU) was successfully fabricated by the method of in-situ interfacial polymerization, wherein 1,4-quinone and thiourea were used as low cost polymer precursors and MWCNT as a conductive support. The π-π stacking interaction between poly(quinone-thiourea) (PQTU) and MWCNT drove the self-assembly of the polymer around MWCNT during the polymerization process, ensuring the formation of the core–sheath nanostructure with ultrathin PQTU layers (10–30 nm in thickness). The unique nanostructure of MWCNT@PQTUs could enhance electronic conductivity, increase active carbonyl (C O) groups for charge storage, promote the Zn2+ diffusion, buffer the volume variation and inhibit the dissolution of the PQTU polymer during the charge − discharge processes. Thanks to these effects, the MWCNT@PQTU cathode exhibited high discharge capacity (120.6 mAh g−1 at 100 mA g−1), excellent rate capability (64.1 mAh g−1 at 1 A g−1) and long cycling stability (81 % capacity retention after 2000 cycles at 500 mA g−1). This work demonstrated that the fabrication of core–sheath nanostructured CNT@polymer cathodes was an effective way to improve the charge storage performance of the quinone-based polymers for Zn-ion batteries. [ABSTRACT FROM AUTHOR]