Toshiba T2N - Manual (Page 235)

5. Programming Language
222 PROSEC T2N
(3) There is no limit to the step number sequence used in 1 SFC
program (including macro programs). However, the initial step
must be made the lowest step number in that sequence.
(See (2) above)
(4) A sequence selection diverges above transitions, and converges
below transitions. Also, a simultaneous sequence diverges above
a steps and converges below a steps.
However, the divergence must end in a corresponding
convergence. Therefore, programs such as the following are not
allowed.