  We construct an elementary, combinatorial kind of topological quantum field
theory, based on curves, surfaces, and orientations. The construction derives
from contact invariants in sutured Floer homology and is essentially an
elaboration of a TQFT defined by Honda--Kazez--Matic. This topological field
theory stores information in binary format on a surface and has "digital"
creation and annihilation operators, giving a toy-model embodiment of "it from
bit".
