let Al be QC-alphabet ; :: thesis: for x being bound_QC-variable of Al
for A being non empty set
for J being interpretation of Al,A
for v being Element of Valuations_in (Al,A)
for S being Element of CQC-Sub-WFF Al
for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let x be bound_QC-variable of Al; :: thesis: for A being non empty set
for J being interpretation of Al,A
for v being Element of Valuations_in (Al,A)
for S being Element of CQC-Sub-WFF Al
for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let A be non empty set ; :: thesis: for J being interpretation of Al,A
for v being Element of Valuations_in (Al,A)
for S being Element of CQC-Sub-WFF Al
for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let J be interpretation of Al,A; :: thesis: for v being Element of Valuations_in (Al,A)
for S being Element of CQC-Sub-WFF Al
for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let v be Element of Valuations_in (Al,A); :: thesis: for S being Element of CQC-Sub-WFF Al
for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let S be Element of CQC-Sub-WFF Al; :: thesis: for xSQ being second_Q_comp of [S,x] st [S,x] is quantifiable holds
( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )

let xSQ be second_Q_comp of [S,x]; :: thesis: ( [S,x] is quantifiable implies ( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S ) )
set S1 = CQCSub_All ([S,x],xSQ);
set z = S_Bound (@ (CQCSub_All ([S,x],xSQ)));
assume A1: [S,x] is quantifiable ; :: thesis: ( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) iff for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S )
thus ( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) implies for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S ) :: thesis: ( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S ) implies for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S )
proof
assume A2: for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ; :: thesis: for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S
let a be Element of A; :: thesis: J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S
NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ) = NEx_Val (v,S,x,xSQ) by A1, Th55;
hence J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S by A2; :: thesis: verum
end;
thus ( ( for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S ) implies for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S ) :: thesis: verum
proof
assume A3: for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val (v,S,x,xSQ)) +* (x | a)) |= S ; :: thesis: for a being Element of A holds J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S
let a be Element of A; :: thesis: J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S
NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ) = NEx_Val (v,S,x,xSQ) by A1, Th55;
hence J,(v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)) . ((NEx_Val ((v . ((S_Bound (@ (CQCSub_All ([S,x],xSQ)))) | a)),S,x,xSQ)) +* (x | a)) |= S by A3; :: thesis: verum
end;