一句话：为 MMSNP 到有限域 CSP 的归约给出新证明，并验证其复杂性二分猜想。
MMSNP 是存在二阶逻辑的一个受限片段，可表达图论与有限模型论中的许多查询。Feder 与 Vardi 曾证明每个 MMSNP 语句都计算等价于有限域约束满足问题（CSP），其概率归约后由 Kun 去随机化。本文给出归约到有限域 CSP 的新证明，不依赖 Kun 的结果，从而得到更强陈述，并验证了 MMSNP 中 CSP 的 Bodirsky-Pinsker 二分猜想。方法上，文章利用每个 MMSNP 语句可描述可数无限 ω-范畴结构上 CSP 的有限并；结合 Hubička 与 Nešetřil 的近期结果，将这些结构扩展为具有有限关系符号和 Ramsey 性质的齐次结构，进而用通用代数方法研究 MMSNP 的计算复杂性。
The logic MMSNP is a restricted fragment of existential second-order logic which allows to express many interesting queries in graph theory and finite model theory. The logic was introduced by Feder and Vardi who showed that every MMSNP sentence is computationally equivalent to a finite-domain constraint satisfaction problem (CSP); the involved probabilistic reductions were derandomized by Kun using explicit constructions of expander structures. We present a new proof of the reduction to finite-domain CSPs that does not rely on the results of Kun. This new proof allows us to obtain a stronger statement and to verify the Bodirsky-Pinsker dichotomy conjecture for CSPs in MMSNP. Our approach uses the fact that every MMSNP sentence describes a finite union of CSPs for countably infinite ω-categorical structures; moreover, by a recent result of Hubička and Nešetřil, these structures can be expanded to homogeneous structures with finite relational signature and the Ramsey property. This allows us to use the universal-algebraic approach to study the computational complexity of MMSNP.