let I, J be Program of ; :: thesis: Directed (I ";" J) = I ";" (Directed J)
A1: (card (stop I)) -' 1 = card I by COMPOS_1:71;
A2: card (stop (Directed I)) = card (stop I) by Lm2;
hence I ";" (Directed J) = (Directed I) +* ((Reloc (J,(card I))) +~ ((halt SCM+FSA),(goto ((card J) + (card I))))) by Th13, A1
.= (Directed I) +* ((Reloc (J,(card I))) +~ ((halt SCM+FSA),(goto (card (I ";" J))))) by Th11
.= ((Directed I) +~ ((halt SCM+FSA),(goto (card (I ";" J))))) +* ((Reloc (J,(card I))) +~ ((halt SCM+FSA),(goto (card (I ";" J))))) by FUNCT_4:127
.= Directed (I ";" J) by FUNCT_7:117, A1, A2 ;
:: thesis: verum