let p, q be Element of CQC-WFF ; :: thesis: for f being FinSequence of CQC-WFF st Suc f = p '&' q & Ant f |= p '&' q holds
Ant f |= p
let f be FinSequence of CQC-WFF ; :: thesis: ( Suc f = p '&' q & Ant f |= p '&' q implies Ant f |= p )
assume A1: ( Suc f = p '&' q & Ant f |= p '&' q ) ; :: thesis: Ant f |= p
let A be non empty set ; :: according to CALCUL_1:def 15 :: thesis: for J being interpretation of A
for v being Element of Valuations_in A st J,v |= Ant f holds
J,v |= p
let J be interpretation of A; :: thesis: for v being Element of Valuations_in A st J,v |= Ant f holds
J,v |= p
let v be Element of Valuations_in A; :: thesis: ( J,v |= Ant f implies J,v |= p )
assume A2: J,v |= Ant f ; :: thesis: J,v |= p
J,v |= p '&' q by A1, A2, Def15;
hence J,v |= p by VALUAT_1:29; :: thesis: verum