let S be Language; R3b S is Correct
now set f =
R3b S;
set R =
P3b S;
set Q =
S -sequents ;
set E =
TheEqSymbOf S;
set N =
TheNorSymbOf S;
set FF =
AllFormulasOf S;
set TT =
AllTermsOf S;
set SS =
AllSymbolsOf S;
set F =
S -firstChar ;
set C =
S -multiCat ;
let X be
set ;
( X is S -correct implies (R3b S) . X is S -correct )assume B0:
X is
S -correct
;
(R3b S) . X is S -correct now let U be non
empty set ;
for I being Element of U -InterpretersOf S
for x being b1 -satisfied set
for psi being wff string of S st [x,psi] in (R3b S) . X holds
I -TruthEval psi = 1set II =
U -InterpretersOf S;
let I be
Element of
U -InterpretersOf S;
for x being I -satisfied set
for psi being wff string of S st [x,psi] in (R3b S) . X holds
I -TruthEval psi = 1let x be
I -satisfied set ;
for psi being wff string of S st [x,psi] in (R3b S) . X holds
I -TruthEval psi = 1let psi be
wff string of
S;
( [x,psi] in (R3b S) . X implies I -TruthEval psi = 1 )set s =
[x,psi];
set TE =
I -TermEval ;
set d =
U -deltaInterpreter ;
CC0:
(
([x,psi] `1) \+\ x = {} &
([x,psi] `2) \+\ psi = {} )
;
assume DD1:
[x,psi] in (R3b S) . X
;
I -TruthEval psi = 1then D1:
(
[x,psi] in S -sequents &
[X,[x,psi]] in P3b S )
by Lm1e;
then
X in dom (P3b S)
by RELAT_1:def 4;
then reconsider Seqts =
X as
S -correct Subset of
(S -sequents) by B0;
reconsider seqt =
[x,psi] as
Element of
S -sequents by DD1, Lm1e;
seqt Rule3b Seqts
by D1, DefP3b;
then consider t1,
t2 being
termal string of
S such that D2:
(
seqt `1 = {((<*(TheEqSymbOf S)*> ^ t1) ^ t2)} &
seqt `2 = (<*(TheEqSymbOf S)*> ^ t2) ^ t1 )
by Def3b;
set phi1 =
(<*(TheEqSymbOf S)*> ^ t1) ^ t2;
set phi2 =
(<*(TheEqSymbOf S)*> ^ t2) ^ t1;
{((<*(TheEqSymbOf S)*> ^ t1) ^ t2)} is
I -satisfied
by D2, CC0, FOMODEL0:29;
then
1
= I -AtomicEval ((<*(TheEqSymbOf S)*> ^ t1) ^ t2)
by FOMODEL2:27;
then
(I -TermEval) . t1 = (I -TermEval) . t2
by Lm36;
then
(
I -AtomicEval ((<*(TheEqSymbOf S)*> ^ t2) ^ t1) = 1 &
(<*(TheEqSymbOf S)*> ^ t2) ^ t1 = psi )
by D2, CC0, Lm36, FOMODEL0:29;
hence
I -TruthEval psi = 1
;
verum end; hence
(R3b S) . X is
S -correct
by FOMODEL2:def 44;
verum end;
hence
R3b S is Correct
by RuleCorr; verum