let A be QC-alphabet ; :: thesis: for p being Element of CQC-WFF A
for X being Subset of (CQC-WFF A) st p in X holds
X |- p
let p be Element of CQC-WFF A; :: thesis: for X being Subset of (CQC-WFF A) st p in X holds
X |- p
let X be Subset of (CQC-WFF A); :: thesis: ( p in X implies X |- p )
X c= Cn X by CQC_THE1:17;
hence ( p in X implies X |- p ) by CQC_THE1:def 8; :: thesis: verum