let n be Element of NAT ; ( n >= 1 implies ZeroTuring computes n const 0 )
assume A1:
n >= 1
; ZeroTuring computes n const 0
now set cs =
n const 0 ;
let s be
All-State of
ZeroTuring ;
for t being Tape of ZeroTuring
for h being Element of NAT
for x being FinSequence of NAT st x in dom (n const 0 ) & s = [the InitS of ZeroTuring ,h,t] & t storeData <*h*> ^ x holds
( s is Accept-Halt & ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> ) )let t be
Tape of
ZeroTuring ;
for h being Element of NAT
for x being FinSequence of NAT st x in dom (n const 0 ) & s = [the InitS of ZeroTuring ,h,t] & t storeData <*h*> ^ x holds
( s is Accept-Halt & ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> ) )let h be
Element of
NAT ;
for x being FinSequence of NAT st x in dom (n const 0 ) & s = [the InitS of ZeroTuring ,h,t] & t storeData <*h*> ^ x holds
( s is Accept-Halt & ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> ) )let x be
FinSequence of
NAT ;
( x in dom (n const 0 ) & s = [the InitS of ZeroTuring ,h,t] & t storeData <*h*> ^ x implies ( s is Accept-Halt & ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> ) ) )assume that A2:
x in dom (n const 0 )
and A3:
s = [the InitS of ZeroTuring ,h,t]
and A4:
t storeData <*h*> ^ x
;
( s is Accept-Halt & ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> ) )
arity (n const 0 ) = n
by COMPUT_1:35;
then A5:
dom (n const 0 ) c= n -tuples_on NAT
by COMPUT_1:24;
then
x in n -tuples_on NAT
by A2;
then
x in { f where f is Element of NAT * : len f = n }
by FINSEQ_2:def 4;
then A6:
ex
f being
Element of
NAT * st
(
x = f &
len f = n )
;
A7:
s = [0 ,h,t]
by A3, Def20;
hence
s is
Accept-Halt
by A1, A4, A6, Th39;
ex h2 being Element of NAT ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> )take h2 =
h;
ex y being Element of NAT st
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> )take y =
0 ;
( (Result s) `2 = h2 & y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> )thus
(Result s) `2 = h2
by A1, A4, A6, A7, Th39;
( y = (n const 0 ) . x & (Result s) `3 storeData <*h2*> ^ <*y*> )thus
y = (n const 0 ) . x
by A2, A5, FUNCOP_1:13;
(Result s) `3 storeData <*h2*> ^ <*y*>
(Result s) `3 storeData <*h2,0 *>
by A1, A4, A6, A7, Th39;
hence
(Result s) `3 storeData <*h2*> ^ <*y*>
by FINSEQ_1:def 9;
verum end;
hence
ZeroTuring computes n const 0
by Def16; verum