let il be Element of NAT ; SUCC il,SCM = {il,(succ il)}
set X = { ((NIC I,il) \ (JUMP I)) where I is Element of the Instructions of SCM : verum } ;
set N = {il,(succ il)};
now let x be
set ;
( ( x in union { ((NIC I,il) \ (JUMP I)) where I is Element of the Instructions of SCM : verum } implies x in {il,(succ il)} ) & ( x in {il,(succ il)} implies b1 in union { ((NIC b2,il) \ (JUMP b2)) where I is Element of the Instructions of SCM : verum } ) )hereby ( x in {il,(succ il)} implies b1 in union { ((NIC b2,il) \ (JUMP b2)) where I is Element of the Instructions of SCM : verum } )
assume
x in union { ((NIC I,il) \ (JUMP I)) where I is Element of the Instructions of SCM : verum }
;
x in {il,(succ il)}then consider Y being
set such that A1:
x in Y
and A2:
Y in { ((NIC I,il) \ (JUMP I)) where I is Element of the Instructions of SCM : verum }
by TARSKI:def 4;
consider i being
Element of the
Instructions of
SCM such that A3:
Y = (NIC i,il) \ (JUMP i)
by A2;
per cases
( i = [0 ,{} ] or ex a, b being Data-Location st i = a := b or ex a, b being Data-Location st i = AddTo a,b or ex a, b being Data-Location st i = SubFrom a,b or ex a, b being Data-Location st i = MultBy a,b or ex a, b being Data-Location st i = Divide a,b or ex k being natural number st i = SCM-goto k or ex a being Data-Location ex k being natural number st i = a =0_goto k or ex a being Data-Location ex k being natural number st i = a >0_goto k )
by AMI_3:69;
suppose
ex
a being
Data-Location ex
k being
natural number st
i = a =0_goto k
;
x in {il,(succ il)}then consider a being
Data-Location ,
k being
natural number such that A10:
i = a =0_goto k
;
A11:
NIC i,
il = {k,(succ il)}
by A10, Th48;
x in NIC i,
il
by A1, A3, XBOOLE_0:def 5;
then A12:
(
x = k or
x = succ il )
by A11, TARSKI:def 2;
x in (NIC i,il) \ {k}
by A1, A3, A10, Th49;
then
not
x in {k}
by XBOOLE_0:def 5;
hence
x in {il,(succ il)}
by A12, TARSKI:def 1, TARSKI:def 2;
verum end; suppose
ex
a being
Data-Location ex
k being
natural number st
i = a >0_goto k
;
x in {il,(succ il)}then consider a being
Data-Location ,
k being
natural number such that A13:
i = a >0_goto k
;
A14:
NIC i,
il = {k,(succ il)}
by A13, Th50;
x in NIC i,
il
by A1, A3, XBOOLE_0:def 5;
then A15:
(
x = k or
x = succ il )
by A14, TARSKI:def 2;
x in (NIC i,il) \ {k}
by A1, A3, A13, Th51;
then
not
x in {k}
by XBOOLE_0:def 5;
hence
x in {il,(succ il)}
by A15, TARSKI:def 1, TARSKI:def 2;
verum end; end;
end; assume A16:
x in {il,(succ il)}
;
b1 in union { ((NIC b2,il) \ (JUMP b2)) where I is Element of the Instructions of SCM : verum } end;
hence
SUCC il,SCM = {il,(succ il)}
by TARSKI:2; verum