SPTP — Chap. 4, p.61

Second introductory paragraph: I agree with the idea of limiting this submission to
metric time (as opposed to logical time), but I find a little too short the justification for
the restriction. After all, real time system are also concerned by correction wrt logical
time. Moreover, at run time, logical time (as represented by interrupt events) is often
the only time of which the system is aware and that it may manipulate. This deserves
certainly consideration, even at modeling level.
Of course take this remark as from somebody whose real-time background deals
mostly with logical time!"

Closed, no change