The different mode that define when the 'when' predicate must be executed.
Note that there is no 'strictEnd' since the end of a binding execution is by default strict.
Note that there is no 'start' (just 'strictStart') since 'then' encompasses 'start'.
Strict modes cancel the binding execution, while non-strict modes just prevent the creation/execution of the
command at a given instant.
The different mode that define when the 'when' predicate must be executed. Note that there is no 'strictEnd' since the end of a binding execution is by default strict. Note that there is no 'start' (just 'strictStart') since 'then' encompasses 'start'. Strict modes cancel the binding execution, while non-strict modes just prevent the creation/execution of the command at a given instant.