let t1, t2 be Integer; ( ex sm, sn, pn being FinSequence of INT st
( len sm = n + 1 & len sn = n + 1 & len pn = n + 1 & ( n < m implies t1 = 0 ) & ( not n < m implies ( sm . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm . (k + 1) = (sm . k) * 2 & not sm . (k + 1) > n ) ) & sm . (i + 1) = (sm . i) * 2 & sm . (i + 1) > n & pn . (i + 1) = 0 & sn . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = (sn . ((i + 1) - (j - 1))) - (sm . ((i + 1) - j)) & pn . ((i + 1) - j) = ((pn . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = sn . ((i + 1) - (j - 1)) & pn . ((i + 1) - j) = (pn . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t1 = pn . 1 ) ) ) ) & ex sm, sn, pn being FinSequence of INT st
( len sm = n + 1 & len sn = n + 1 & len pn = n + 1 & ( n < m implies t2 = 0 ) & ( not n < m implies ( sm . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm . (k + 1) = (sm . k) * 2 & not sm . (k + 1) > n ) ) & sm . (i + 1) = (sm . i) * 2 & sm . (i + 1) > n & pn . (i + 1) = 0 & sn . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = (sn . ((i + 1) - (j - 1))) - (sm . ((i + 1) - j)) & pn . ((i + 1) - j) = ((pn . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = sn . ((i + 1) - (j - 1)) & pn . ((i + 1) - j) = (pn . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t2 = pn . 1 ) ) ) ) implies t1 = t2 )
assume that
A109:
ex sm, sn, pn being FinSequence of INT st
( len sm = n + 1 & len sn = n + 1 & len pn = n + 1 & ( n < m implies t1 = 0 ) & ( not n < m implies ( sm . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm . (k + 1) = (sm . k) * 2 & not sm . (k + 1) > n ) ) & sm . (i + 1) = (sm . i) * 2 & sm . (i + 1) > n & pn . (i + 1) = 0 & sn . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = (sn . ((i + 1) - (j - 1))) - (sm . ((i + 1) - j)) & pn . ((i + 1) - j) = ((pn . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = sn . ((i + 1) - (j - 1)) & pn . ((i + 1) - j) = (pn . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t1 = pn . 1 ) ) ) )
and
A110:
ex sm, sn, pn being FinSequence of INT st
( len sm = n + 1 & len sn = n + 1 & len pn = n + 1 & ( n < m implies t2 = 0 ) & ( not n < m implies ( sm . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm . (k + 1) = (sm . k) * 2 & not sm . (k + 1) > n ) ) & sm . (i + 1) = (sm . i) * 2 & sm . (i + 1) > n & pn . (i + 1) = 0 & sn . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = (sn . ((i + 1) - (j - 1))) - (sm . ((i + 1) - j)) & pn . ((i + 1) - j) = ((pn . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn . ((i + 1) - (j - 1)) >= sm . ((i + 1) - j) implies ( sn . ((i + 1) - j) = sn . ((i + 1) - (j - 1)) & pn . ((i + 1) - j) = (pn . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t2 = pn . 1 ) ) ) )
; t1 = t2
consider sm1, sn1, pn1 being FinSequence of INT such that
len sm1 = n + 1
and
len sn1 = n + 1
and
len pn1 = n + 1
and
A111:
( n < m implies t1 = 0 )
and
A112:
( not n < m implies ( sm1 . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm1 . (k + 1) = (sm1 . k) * 2 & not sm1 . (k + 1) > n ) ) & sm1 . (i + 1) = (sm1 . i) * 2 & sm1 . (i + 1) > n & pn1 . (i + 1) = 0 & sn1 . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn1 . ((i + 1) - (j - 1)) >= sm1 . ((i + 1) - j) implies ( sn1 . ((i + 1) - j) = (sn1 . ((i + 1) - (j - 1))) - (sm1 . ((i + 1) - j)) & pn1 . ((i + 1) - j) = ((pn1 . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn1 . ((i + 1) - (j - 1)) >= sm1 . ((i + 1) - j) implies ( sn1 . ((i + 1) - j) = sn1 . ((i + 1) - (j - 1)) & pn1 . ((i + 1) - j) = (pn1 . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t1 = pn1 . 1 ) ) )
by A109;
consider sm2, sn2, pn2 being FinSequence of INT such that
len sm2 = n + 1
and
len sn2 = n + 1
and
len pn2 = n + 1
and
A113:
( n < m implies t2 = 0 )
and
A114:
( not n < m implies ( sm2 . 1 = m & ex i being Integer st
( 1 <= i & i <= n & ( for k being Integer st 1 <= k & k < i holds
( sm2 . (k + 1) = (sm2 . k) * 2 & not sm2 . (k + 1) > n ) ) & sm2 . (i + 1) = (sm2 . i) * 2 & sm2 . (i + 1) > n & pn2 . (i + 1) = 0 & sn2 . (i + 1) = n & ( for j being Integer st 1 <= j & j <= i holds
( ( sn2 . ((i + 1) - (j - 1)) >= sm2 . ((i + 1) - j) implies ( sn2 . ((i + 1) - j) = (sn2 . ((i + 1) - (j - 1))) - (sm2 . ((i + 1) - j)) & pn2 . ((i + 1) - j) = ((pn2 . ((i + 1) - (j - 1))) * 2) + 1 ) ) & ( not sn2 . ((i + 1) - (j - 1)) >= sm2 . ((i + 1) - j) implies ( sn2 . ((i + 1) - j) = sn2 . ((i + 1) - (j - 1)) & pn2 . ((i + 1) - j) = (pn2 . ((i + 1) - (j - 1))) * 2 ) ) ) ) & t2 = pn2 . 1 ) ) )
by A110;
now t1 = t2per cases
( n < m or n >= m )
;
suppose A115:
n >= m
;
t1 = t2then consider i1 being
Integer such that A116:
1
<= i1
and
i1 <= n
and A117:
for
k being
Integer st 1
<= k &
k < i1 holds
(
sm1 . (k + 1) = (sm1 . k) * 2 & not
sm1 . (k + 1) > n )
and A118:
sm1 . (i1 + 1) = (sm1 . i1) * 2
and A119:
sm1 . (i1 + 1) > n
and A120:
pn1 . (i1 + 1) = 0
and A121:
sn1 . (i1 + 1) = n
and A122:
for
j being
Integer st 1
<= j &
j <= i1 holds
( (
sn1 . ((i1 + 1) - (j - 1)) >= sm1 . ((i1 + 1) - j) implies (
sn1 . ((i1 + 1) - j) = (sn1 . ((i1 + 1) - (j - 1))) - (sm1 . ((i1 + 1) - j)) &
pn1 . ((i1 + 1) - j) = ((pn1 . ((i1 + 1) - (j - 1))) * 2) + 1 ) ) & ( not
sn1 . ((i1 + 1) - (j - 1)) >= sm1 . ((i1 + 1) - j) implies (
sn1 . ((i1 + 1) - j) = sn1 . ((i1 + 1) - (j - 1)) &
pn1 . ((i1 + 1) - j) = (pn1 . ((i1 + 1) - (j - 1))) * 2 ) ) )
and A123:
t1 = pn1 . 1
by A112;
reconsider ii1 =
i1 as
Element of
NAT by A116, INT_1:3;
defpred S1[
Nat]
means ( 1
<= $1 & $1
<= i1 + 1 implies
sm1 . $1
= sm2 . $1 );
defpred S2[
Nat]
means ( 1
<= $1 & $1
<= i1 + 1 implies
pn1 . (((ii1 + 1) + 1) -' $1) = pn2 . (((ii1 + 1) + 1) -' $1) );
defpred S3[
Nat]
means ( 1
<= $1 & $1
<= i1 + 1 implies
sn1 . (((ii1 + 1) + 1) -' $1) = sn2 . (((ii1 + 1) + 1) -' $1) );
consider i2 being
Integer such that A124:
1
<= i2
and
i2 <= n
and A125:
for
k being
Integer st 1
<= k &
k < i2 holds
(
sm2 . (k + 1) = (sm2 . k) * 2 & not
sm2 . (k + 1) > n )
and A126:
sm2 . (i2 + 1) = (sm2 . i2) * 2
and A127:
sm2 . (i2 + 1) > n
and A128:
pn2 . (i2 + 1) = 0
and A129:
sn2 . (i2 + 1) = n
and A130:
for
j being
Integer st 1
<= j &
j <= i2 holds
( (
sn2 . ((i2 + 1) - (j - 1)) >= sm2 . ((i2 + 1) - j) implies (
sn2 . ((i2 + 1) - j) = (sn2 . ((i2 + 1) - (j - 1))) - (sm2 . ((i2 + 1) - j)) &
pn2 . ((i2 + 1) - j) = ((pn2 . ((i2 + 1) - (j - 1))) * 2) + 1 ) ) & ( not
sn2 . ((i2 + 1) - (j - 1)) >= sm2 . ((i2 + 1) - j) implies (
sn2 . ((i2 + 1) - j) = sn2 . ((i2 + 1) - (j - 1)) &
pn2 . ((i2 + 1) - j) = (pn2 . ((i2 + 1) - (j - 1))) * 2 ) ) )
and A131:
t2 = pn2 . 1
by A114, A115;
reconsider ii2 =
i2 as
Element of
NAT by A124, INT_1:3;
A132:
now not i2 < i1end; A148:
now not i1 < i2end; then A164:
i1 = i2
by A132, XXREAL_0:1;
A165:
ii1 < ii1 + 1
by NAT_1:13;
A166:
for
kk being
Nat st
S1[
kk] holds
S1[
kk + 1]
proof
let kk be
Nat;
( S1[kk] implies S1[kk + 1] )
assume A167:
S1[
kk]
;
S1[kk + 1]
( 1
<= kk + 1 &
kk + 1
<= i1 + 1 implies
sm1 . (kk + 1) = sm2 . (kk + 1) )
proof
assume that
1
<= kk + 1
and A168:
kk + 1
<= i1 + 1
;
sm1 . (kk + 1) = sm2 . (kk + 1)
end;
hence
S1[
kk + 1]
;
verum
end; A173:
S1[
0 ]
;
A174:
for
jj being
Nat holds
S1[
jj]
from NAT_1:sch 2(A173, A166);
A175:
for
jj being
Integer st 1
<= jj &
jj <= i1 + 1 holds
sm1 . jj = sm2 . jj
A178:
for
kk being
Nat st
S3[
kk] holds
S3[
kk + 1]
proof
let kk be
Nat;
( S3[kk] implies S3[kk + 1] )
assume A179:
S3[
kk]
;
S3[kk + 1]
( 1
<= kk + 1 &
kk + 1
<= i1 + 1 implies
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1)) )
proof
assume that
1
<= kk + 1
and A180:
kk + 1
<= i1 + 1
;
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1))
A181:
(kk + 1) - 1
<= (i2 + 1) - 1
by A164, A180, XREAL_1:9;
per cases
( 0 < kk or 0 >= kk )
;
suppose A182:
0 < kk
;
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1))A183:
kk < i1 + 1
by A164, A165, A181, XXREAL_0:2;
then
(i1 + 1) - kk > 0
by XREAL_1:50;
then A184:
(ii1 + 1) -' kk = (i1 + 1) - kk
by XREAL_0:def 2;
A185:
0 + 1
<= kk
by A182, NAT_1:13;
then A186:
kk - 1
>= 0
by XREAL_1:48;
kk -' 1
<= kk
by NAT_D:35;
then
kk -' 1
< i1 + 1
by A183, XXREAL_0:2;
then
(i1 + 1) - (kk -' 1) >= 0
by XREAL_1:48;
then A187:
(ii1 + 1) -' (kk -' 1) =
(i1 + 1) - (kk -' 1)
by XREAL_0:def 2
.=
(i1 + 1) - (kk - 1)
by A186, XREAL_0:def 2
;
now ( ( kk <= i2 & sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1)) ) or ( kk > i2 & contradiction ) )per cases
( kk <= i2 or kk > i2 )
;
case A188:
kk <= i2
;
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1))
ii1 < ii1 + 1
by NAT_1:13;
then
kk < i1 + 1
by A164, A188, XXREAL_0:2;
then A189:
(i1 + 1) - kk > 0
by XREAL_1:50;
then
(ii1 + 1) -' kk = (i1 + 1) - kk
by XREAL_0:def 2;
then A190:
(ii1 + 1) -' kk >= 0 + 1
by A189, NAT_1:13;
A191:
(
(ii1 + 1) -' kk <= i1 + 1 &
((ii1 + 1) + 1) -' (kk + 1) = (ii1 + 1) -' kk )
by Th1, NAT_D:35;
A192:
( not
sn2 . ((ii1 + 1) -' (kk -' 1)) >= sm2 . ((ii1 + 1) -' kk) implies (
sn2 . ((ii1 + 1) -' kk) = sn2 . ((ii1 + 1) -' (kk -' 1)) &
pn2 . ((ii1 + 1) -' kk) = (pn2 . ((ii1 + 1) -' (kk -' 1))) * 2 ) )
by A130, A164, A185, A187, A184, A188;
kk - 1
>= 0
by A185, XREAL_1:48;
then
kk -' 1
= kk - 1
by XREAL_0:def 2;
then
kk = (kk -' 1) + 1
;
then A193:
((ii1 + 1) + 1) -' kk = (ii1 + 1) -' (kk -' 1)
by Th1;
A194:
(
sn2 . ((ii1 + 1) -' (kk -' 1)) >= sm2 . ((ii1 + 1) -' kk) implies (
sn2 . ((ii1 + 1) -' kk) = (sn2 . ((ii1 + 1) -' (kk -' 1))) - (sm2 . ((ii1 + 1) -' kk)) &
pn2 . ((ii1 + 1) -' kk) = ((pn2 . ((ii1 + 1) -' (kk -' 1))) * 2) + 1 ) )
by A130, A164, A185, A187, A184, A188;
A195:
( not
sn1 . ((ii1 + 1) -' (kk -' 1)) >= sm1 . ((ii1 + 1) -' kk) implies (
sn1 . ((ii1 + 1) -' kk) = sn1 . ((ii1 + 1) -' (kk -' 1)) &
pn1 . ((ii1 + 1) -' kk) = (pn1 . ((ii1 + 1) -' (kk -' 1))) * 2 ) )
by A122, A164, A185, A187, A184, A188;
(
sn1 . ((ii1 + 1) -' (kk -' 1)) >= sm1 . ((ii1 + 1) -' kk) implies (
sn1 . ((ii1 + 1) -' kk) = (sn1 . ((ii1 + 1) -' (kk -' 1))) - (sm1 . ((ii1 + 1) -' kk)) &
pn1 . ((ii1 + 1) -' kk) = ((pn1 . ((ii1 + 1) -' (kk -' 1))) * 2) + 1 ) )
by A122, A164, A185, A187, A184, A188;
hence
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1))
by A164, A175, A179, A182, A188, A195, A194, A192, A190, A193, A191, NAT_1:13;
verum end; case
kk > i2
;
contradictionhence
contradiction
by A181;
verum end; end; end; hence
sn1 . (((ii1 + 1) + 1) -' (kk + 1)) = sn2 . (((ii1 + 1) + 1) -' (kk + 1))
;
verum end; end;
end;
hence
S3[
kk + 1]
;
verum
end; A197:
S3[
0 ]
;
A198:
for
jj being
Nat holds
S3[
jj]
from NAT_1:sch 2(A197, A178);
A199:
for
kk being
Nat st
S2[
kk] holds
S2[
kk + 1]
proof
let kk be
Nat;
( S2[kk] implies S2[kk + 1] )
assume A200:
S2[
kk]
;
S2[kk + 1]
( 1
<= kk + 1 &
kk + 1
<= i1 + 1 implies
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1)) )
proof
assume that
1
<= kk + 1
and A201:
kk + 1
<= i1 + 1
;
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1))
A202:
(kk + 1) - 1
<= (i2 + 1) - 1
by A164, A201, XREAL_1:9;
per cases
( 0 < kk or 0 >= kk )
;
suppose A203:
0 < kk
;
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1))A204:
kk -' 1
< (kk -' 1) + 1
by NAT_1:13;
kk < ii1 + 1
by A201, NAT_1:13;
then
(i1 + 1) - kk > 0
by XREAL_1:50;
then A205:
(ii1 + 1) -' kk = (i1 + 1) - kk
by XREAL_0:def 2;
A206:
0 + 1
<= kk
by A203, NAT_1:13;
then A207:
kk - 1
>= 0
by XREAL_1:48;
then
kk - 1
= kk -' 1
by XREAL_0:def 2;
then
kk -' 1
< i2
by A202, A204, XXREAL_0:2;
then
kk -' 1
< i2 + 1
by A164, A165, XXREAL_0:2;
then
(i1 + 1) - (kk -' 1) >= 0
by A164, XREAL_1:48;
then A208:
(ii1 + 1) -' (kk -' 1) =
(i1 + 1) - (kk -' 1)
by XREAL_0:def 2
.=
(i1 + 1) - (kk - 1)
by A207, XREAL_0:def 2
;
now ( ( kk <= i2 & pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1)) ) or ( kk > i2 & contradiction ) )per cases
( kk <= i2 or kk > i2 )
;
case A209:
kk <= i2
;
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1))
ii1 < ii1 + 1
by NAT_1:13;
then A210:
kk < i1 + 1
by A164, A209, XXREAL_0:2;
then A211:
(i1 + 1) - kk > 0
by XREAL_1:50;
then
(ii1 + 1) -' kk = (i1 + 1) - kk
by XREAL_0:def 2;
then
(ii1 + 1) -' kk >= 0 + 1
by A211, NAT_1:13;
then A212:
sm1 . ((ii1 + 1) -' kk) = sm2 . ((ii1 + 1) -' kk)
by A175, NAT_D:35;
kk - 1
>= 0
by A206, XREAL_1:48;
then
kk -' 1
= kk - 1
by XREAL_0:def 2;
then
kk = (kk -' 1) + 1
;
then A213:
((ii1 + 1) + 1) -' kk = (ii1 + 1) -' (kk -' 1)
by Th1;
A214:
( not
sn1 . ((ii1 + 1) -' (kk -' 1)) >= sm1 . ((ii1 + 1) -' kk) implies (
sn1 . ((ii1 + 1) -' kk) = sn1 . ((ii1 + 1) -' (kk -' 1)) &
pn1 . ((ii1 + 1) -' kk) = (pn1 . ((ii1 + 1) -' (kk -' 1))) * 2 ) )
by A122, A164, A206, A208, A205, A209;
A215:
((ii1 + 1) + 1) -' (kk + 1) = (ii1 + 1) -' kk
by Th1;
A216:
( not
sn2 . ((ii1 + 1) -' (kk -' 1)) >= sm2 . ((ii1 + 1) -' kk) implies (
sn2 . ((ii1 + 1) -' kk) = sn2 . ((ii1 + 1) -' (kk -' 1)) &
pn2 . ((ii1 + 1) -' kk) = (pn2 . ((ii1 + 1) -' (kk -' 1))) * 2 ) )
by A130, A164, A206, A208, A205, A209;
A217:
(
sn2 . ((ii1 + 1) -' (kk -' 1)) >= sm2 . ((ii1 + 1) -' kk) implies (
sn2 . ((ii1 + 1) -' kk) = (sn2 . ((ii1 + 1) -' (kk -' 1))) - (sm2 . ((ii1 + 1) -' kk)) &
pn2 . ((ii1 + 1) -' kk) = ((pn2 . ((ii1 + 1) -' (kk -' 1))) * 2) + 1 ) )
by A130, A164, A206, A208, A205, A209;
(
sn1 . ((ii1 + 1) -' (kk -' 1)) >= sm1 . ((ii1 + 1) -' kk) implies (
sn1 . ((ii1 + 1) -' kk) = (sn1 . ((ii1 + 1) -' (kk -' 1))) - (sm1 . ((ii1 + 1) -' kk)) &
pn1 . ((ii1 + 1) -' kk) = ((pn1 . ((ii1 + 1) -' (kk -' 1))) * 2) + 1 ) )
by A122, A164, A206, A208, A205, A209;
hence
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1))
by A198, A200, A206, A214, A217, A216, A210, A213, A212, A215;
verum end; case
kk > i2
;
contradictionhence
contradiction
by A202;
verum end; end; end; hence
pn1 . (((ii1 + 1) + 1) -' (kk + 1)) = pn2 . (((ii1 + 1) + 1) -' (kk + 1))
;
verum end; end;
end;
hence
S2[
kk + 1]
;
verum
end; A219:
S2[
0 ]
;
A220:
for
jj being
Nat holds
S2[
jj]
from NAT_1:sch 2(A219, A199);
A221:
for
jj being
Integer st 1
<= jj &
jj <= i1 + 1 holds
pn1 . (((i1 + 1) + 1) - jj) = pn2 . (((i1 + 1) + 1) - jj)
( 1
<= 1
+ ii1 &
((i1 + 1) + 1) - (i1 + 1) = 1 )
by NAT_1:11;
hence
t1 = t2
by A123, A131, A221;
verum end; end; end;
hence
t1 = t2
; verum