let l be Instruction of SCM ; InsCode l <= 8
( l 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} } or l 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} } )
by XBOOLE_0:def 3;
then A1:
( l in {[SCM-Halt ,{} ]} \/ { [J,<*a*>] where J is Element of Segm 9, a is Element of NAT : J = 6 } or l in { [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} } or l 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} } )
by XBOOLE_0:def 3;
per cases
( l in {[SCM-Halt ,{} ]} or l in { [J,<*a*>] where J is Element of Segm 9, a is Element of NAT : J = 6 } or l in { [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} } or l 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} } )
by A1, XBOOLE_0:def 3;
suppose
l 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} }
;
InsCode l <= 8then
ex
I being
Element of
Segm 9 ex
b,
c being
Element of
SCM-Data-Loc st
(
l = [I,<*b,c*>] &
I in {1,2,3,4,5} )
;
then
l `1 in {1,2,3,4,5}
by MCART_1:7;
then
(
l `1 = 1 or
l `1 = 2 or
l `1 = 3 or
l `1 = 4 or
l `1 = 5 )
by ENUMSET1:def 3;
hence
InsCode l <= 8
;
verum end; end;