let I, J, K be Program of SCM+FSA; (I ';' J) ';' K = I ';' (J ';' K)
A1: ProgramPart (Relocated ((J ';' K),(card I))) =
(ProgramPart (Relocated ((Directed J),(card I)))) +* (ProgramPart (Relocated ((ProgramPart (Relocated (K,(card J)))),(card I))))
by Th21
.=
(ProgramPart (Relocated ((Directed J),(card I)))) +* (ProgramPart (Relocated (K,((card J) + (card I)))))
by Th22
;
thus (I ';' J) ';' K =
(I ';' (Directed J)) +* (ProgramPart (Relocated (K,(card (I ';' J)))))
by Th66
.=
(Directed I) +* ((ProgramPart (Relocated ((Directed J),(card I)))) +* (ProgramPart (Relocated (K,(card (I ';' J))))))
by FUNCT_4:15
.=
I ';' (J ';' K)
by A1, Th61
; verum