Definition: The expression (s STRT t)
states that the temporal beginning of an event s
or the beginning of the validity of a state of affairs s
is determined by the second argument t
, which can be another situation, a moment, or a period of time. If the second argument of the expression (x STRT y)
denotes a situation (i.e. y ∈ si
), then the temporal beginning of x
is determined by the beginning of that time interval ty
which is attached to the situation y
(ty
= time interval of the validity of y
). In this case, the duration of y
or ty
must not be longer than that of situation x
. The relation STRT
is defined only in those cases where the first argument has a certain duration. See also FIN.