  We experimentally demonstrate that highly structured distributions of work
emerge during even the simple task of erasing a single bit. These are
signatures of a refined suite of time-reversal symmetries in distinct
functional classes of microscopic trajectories. As a consequence, we introduce
a broad family of conditional fluctuation theorems that the component work
distributions must satisfy. Since they identify entropy production, the
component work distributions encode both the frequency of various mechanisms of
success and failure during computing, as well giving improved estimates of the
total irreversibly-dissipated heat. This new diagnostic tool provides strong
evidence that thermodynamic computing at the nanoscale can be constructively
harnessed. We experimentally verify this functional decomposition and the new
class of fluctuation theorems by measuring transitions between flux states in a
superconducting circuit.
