3 papers
math.LO2026
Robinson Splitting Theorem and Induction
Yong Liu, Cheng Peng, Mengzhou Sun
The Robinson Splitting Theorem states that a c.e. degree splits over any low c.e. degree . We prove that a weaker version of this theorem holds…
math.LO2025
Bi-Isolated d.c.e. Degrees and Induction
Yong Liu, Cheng Peng
A Turing degree is d.c.e. if it contains a set that is the difference of two c.e. sets. A d.c.e. degree is isolated if there exists a c.e. degree $\mathbf{a}<\mathbf{d…
math.LO2025
Isolated d.c.e. degrees and induction
Yiqun Liu, Yong Liu, Cheng Peng
A Turing degree is d.c.e. if it contains a set that is the difference of two c.e. sets. A d.c.e. degree is isolated by a c.e. degree if all c.e…