Lecture 6: Paper folding: overview, definitions, connectivity, 1D flat foldability, 2D map folding
Page 4: Crease pattern, flat folding, flat foldable crease pattern, mountain and valley creases, mountain-valley assignment, mountain-valley pattern. Characterization of flat foldability of 1D crease patterns and mountain-valley assignments. Linear-time algorithm.
You can view the paper by Arkin, Bender, Demaine, Demaine, Mitchell, Sethia, and Skiena on 1D flat foldability and 2D map folding.
These are rough, personal lecture notes handwritten by Erik Demaine used during lecture. Their primary purpose is for reading/review by students of the class.