18.404J/6.840J The Theory of Computation(Fall 2020, MIT OCW). Instructor: Prof. Michael Sipser. This course emphasizes computability and computational complexity theory. Topics include regular and context-free languages, decidable and undecidable problems, reducibility, recursive function theory, time and space measures on computation, completeness, hierarchy theorems, inherently complex problems, oracles, probabilistic computation, and interactive proof systems.
(from ocw.mit.edu)
Lecture 21 - Hierarchy Theorems
Quickly reviewed last lecture. Finished Immerman-Szelepcsenyi theorem: NL = coNL. Introduced and proved the time and space hierarchy theorems. Discussed using the hierarchy theorems to separate certain complexity classes.