theorem Th88:
for
Al being
QC-alphabet for
x being
bound_QC-variable of
Al for
A being non
empty set for
J being
interpretation of
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 & ( for
v being
Element of
Valuations_in (
Al,
A) holds
(
J,
v |= CQC_Sub S iff
J,
v . (Val_S (v,S)) |= S ) ) holds
for
v being
Element of
Valuations_in (
Al,
A) holds
(
J,
v |= CQC_Sub (CQCSub_All ([S,x],xSQ)) iff
J,
v . (Val_S (v,(CQCSub_All ([S,x],xSQ)))) |= CQCSub_All (
[S,x],
xSQ) )