part of is part of part of precedes precedes Precedes defines a strict partial order on occurrents. (Elucidation) precedes is a relation between occurrents o, o' such that if t is the temporal extent of o & t' is the temporal extent of o' then either the last instant of o is before the first instant of o' or the last instant of o is the first instant of o' & neither o nor o' are temporal instants Each temporal region is its own temporal extent. The temporal extent of a spatiotemporal region is the temporal region it temporally projects onto. The temporal extent of a process or process boundary that occupies temporal region t is t. 270-BFO The temporal region occupied by Mary's birth precedes the temporal region occupied by Mary's death. precedes x precedes y if and only if the time point at which x ends is before or equivalent to the time point at which y starts. Formally: x precedes y iff ω(x) <= α(y), where α is a function that maps a process to a start point, and ω is a function that maps a process to an end point. temporal relation temporally related to occurrent occurrent