一句话：提出弱 λ-演算的实现模型，在按名与按值策略下同时保持时间与空间复杂度不变。
论文关注 λ-演算实现中长期存在的时间不变性与空间不变性难以兼得的问题。作者为弱 λ-演算提出一种实现模型，同时覆盖 call-by-name 与 call-by-value 归约策略，并通过将内联（inlining）视为空间优化来控制中间项膨胀。该模型能够模拟任意弱按名或按值归约序列：其时间复杂度为所模拟 β-步数的多项式，空间复杂度为最大中间项大小的线性。由此，论文以简洁方式解决了 λ-演算实现中时间与空间复杂度无法同时保持不变的经典张力。
We propose an implementation model for the evaluation of the weak λ-calculus, which is invariant for both time and space complexity, in both call-by-name and call-by-value strategies. In other words, this model provides an implementation of any weak call-by-name or weak call-by-value λ-calculus reduction sequence, whose time complexity is polynomial in the number of simulated β-steps, and whose space complexity is linear in the size of the largest intermediate term. This solves in an elegant way the well-known tension between time-invariance and space-invariance in the implementation of the λ-calculus.
@article{Balabonski26,
title = {Inlining as a Space Optimization: A Simple Time- and Space-Invariant Implementation of the Weak Lambda-Calculus},
author = {Thibaut Balabonski},
journal = {Proceedings of the ACM on Programming Languages},
volume = {10},
number = {ICFP},
year = {2026},
doi = {10.1145/3828705}
}