defpred S1[ Element of QC-Sub-WFF ] means ( $1 is Element of CQC-Sub-WFF implies P1[$1] );
A2: for k being Element of NAT
for P being QC-pred_symbol of k
for ll being QC-variable_list of k
for e being Element of vSUB holds S1[ Sub_P P,ll,e]
proof
let k be Element of NAT ; :: thesis: for P being QC-pred_symbol of k
for ll being QC-variable_list of k
for e being Element of vSUB holds S1[ Sub_P P,ll,e]

let P be QC-pred_symbol of k; :: thesis: for ll being QC-variable_list of k
for e being Element of vSUB holds S1[ Sub_P P,ll,e]

let ll be QC-variable_list of k; :: thesis: for e being Element of vSUB holds S1[ Sub_P P,ll,e]
let e be Element of vSUB ; :: thesis: S1[ Sub_P P,ll,e]
assume Sub_P P,ll,e is Element of CQC-Sub-WFF ; :: thesis: P1[ Sub_P P,ll,e]
then A3: Sub_P P,ll,e in CQC-Sub-WFF ;
A4: Sub_P P,ll,e = [(P ! ll),e] by Th9;
consider S1 being Element of QC-Sub-WFF such that
A5: ( Sub_P P,ll,e = S1 & S1 `1 is Element of CQC-WFF ) by A3;
P ! ll is Element of CQC-WFF by A4, A5, MCART_1:7;
then ( { (ll . i) where i is Element of NAT : ( 1 <= i & i <= len ll & ll . i in free_QC-variables ) } = {} & { (ll . j) where j is Element of NAT : ( 1 <= j & j <= len ll & ll . j in fixed_QC-variables ) } = {} ) by CQC_LANG:17;
then ll is CQC-variable_list of k by CQC_LANG:15;
hence P1[ Sub_P P,ll,e] by A1; :: thesis: verum
end;
A6: for S being Element of QC-Sub-WFF st S is Sub_VERUM holds
S1[S] by A1;
A7: for S being Element of QC-Sub-WFF st S1[S] holds
S1[ Sub_not S]
proof
let S be Element of QC-Sub-WFF ; :: thesis: ( S1[S] implies S1[ Sub_not S] )
assume A8: S1[S] ; :: thesis: S1[ Sub_not S]
assume Sub_not S is Element of CQC-Sub-WFF ; :: thesis: P1[ Sub_not S]
then Sub_not S in CQC-Sub-WFF ;
then consider S' being Element of QC-Sub-WFF such that
A9: ( Sub_not S = S' & S' `1 is Element of CQC-WFF ) ;
S' `1 = 'not' (S `1 ) by A9, MCART_1:7;
then S `1 is Element of CQC-WFF by A9, CQC_LANG:18;
then S in CQC-Sub-WFF ;
hence P1[ Sub_not S] by A1, A8; :: thesis: verum
end;
A10: for S1, S2 being Element of QC-Sub-WFF st S1 `2 = S2 `2 & S1[S1] & S1[S2] holds
S1[ Sub_& S1,S2]
proof
let S1, S2 be Element of QC-Sub-WFF ; :: thesis: ( S1 `2 = S2 `2 & S1[S1] & S1[S2] implies S1[ Sub_& S1,S2] )
assume A11: ( S1 `2 = S2 `2 & S1[S1] & S1[S2] ) ; :: thesis: S1[ Sub_& S1,S2]
assume Sub_& S1,S2 is Element of CQC-Sub-WFF ; :: thesis: P1[ Sub_& S1,S2]
then Sub_& S1,S2 in CQC-Sub-WFF ;
then consider S' being Element of QC-Sub-WFF such that
A12: ( Sub_& S1,S2 = S' & S' `1 is Element of CQC-WFF ) ;
Sub_& S1,S2 = [((S1 `1 ) '&' (S2 `1 )),(S1 `2 )] by A11, Def21;
then S' `1 = (S1 `1 ) '&' (S2 `1 ) by A12, MCART_1:7;
then A13: ( S1 `1 is Element of CQC-WFF & S2 `1 is Element of CQC-WFF ) by A12, CQC_LANG:19;
then A14: S1 in CQC-Sub-WFF ;
S2 in CQC-Sub-WFF by A13;
hence P1[ Sub_& S1,S2] by A1, A11, A14; :: thesis: verum
end;
A15: for x being bound_QC-variable
for S being Element of QC-Sub-WFF
for SQ being second_Q_comp of [S,x] st [S,x] is quantifiable & S1[S] holds
S1[ Sub_All [S,x],SQ]
proof
let x be bound_QC-variable; :: thesis: for S being Element of QC-Sub-WFF
for SQ being second_Q_comp of [S,x] st [S,x] is quantifiable & S1[S] holds
S1[ Sub_All [S,x],SQ]

let S be Element of QC-Sub-WFF ; :: thesis: for SQ being second_Q_comp of [S,x] st [S,x] is quantifiable & S1[S] holds
S1[ Sub_All [S,x],SQ]

let SQ be second_Q_comp of [S,x]; :: thesis: ( [S,x] is quantifiable & S1[S] implies S1[ Sub_All [S,x],SQ] )
assume A16: ( [S,x] is quantifiable & S1[S] ) ; :: thesis: S1[ Sub_All [S,x],SQ]
assume Sub_All [S,x],SQ is Element of CQC-Sub-WFF ; :: thesis: P1[ Sub_All [S,x],SQ]
then Sub_All [S,x],SQ in CQC-Sub-WFF ;
then consider S' being Element of QC-Sub-WFF such that
A17: ( Sub_All [S,x],SQ = S' & S' `1 is Element of CQC-WFF ) ;
Sub_All [S,x],SQ = [(All ([S,x] `2 ),(([S,x] `1 ) `1 )),SQ] by A16, Def24;
then S' `1 = All ([S,x] `2 ),(([S,x] `1 ) `1 ) by A17, MCART_1:7;
then A18: ([S,x] `1 ) `1 is Element of CQC-WFF by A17, CQC_LANG:23;
[S,x] `1 = S by MCART_1:7;
then S in CQC-Sub-WFF by A18;
hence P1[ Sub_All [S,x],SQ] by A1, A16; :: thesis: verum
end;
for S being Element of QC-Sub-WFF holds S1[S] from SUBSTUT1:sch 1(A2, A6, A7, A10, A15);
hence for S being Element of CQC-Sub-WFF holds P1[S] ; :: thesis: verum