let ins be Instruction of SCM ; ( InsCode ins = 0 implies ins = halt SCM )
assume A1:
InsCode ins = 0
; ins = halt SCM
now assume
ins in { [I,{} ,<*b,c*>] where I is Element of Segm 9, b, c is Element of SCM-Data-Loc : I in {1,2,3,4,5} }
;
contradictionthen
ex
I being
Element of
Segm 9 ex
b,
c being
Element of
SCM-Data-Loc st
(
ins = [I,{} ,<*b,c*>] &
I in {1,2,3,4,5} )
;
hence
contradiction
by A1, RECDEF_2:def 1;
verum end;
then A3:
ins in ({[SCM-Halt ,{} ,{} ]} \/ { [J,<*a*>,{} ] where J is Element of Segm 9, a is Element of NAT : J = 6 } ) \/ { [K,<*a1*>,<*b1*>] where K is Element of Segm 9, a1 is Element of NAT , b1 is Element of SCM-Data-Loc : K in {7,8} }
by XBOOLE_0:def 3;
then
ins in {[SCM-Halt ,{} ,{} ]} \/ { [J,<*a*>,{} ] where J is Element of Segm 9, a is Element of NAT : J = 6 }
by A3, XBOOLE_0:def 3;
then
ins in {[SCM-Halt ,{} ,{} ]}
by A2, XBOOLE_0:def 3;
hence
ins = halt SCM
by AMI_3:71, TARSKI:def 1; verum