let p, q be Element of CQC-WFF ; for f being FinSequence of CQC-WFF st Ant f |= p '&' q holds
Ant f |= q
let f be FinSequence of CQC-WFF ; ( Ant f |= p '&' q implies Ant f |= q )
assume A1:
Ant f |= p '&' q
; Ant f |= q
let A be non empty set ; CALCUL_1:def 15 for J being interpretation of A
for v being Element of Valuations_in A st J,v |= Ant f holds
J,v |= q
let J be interpretation of A; for v being Element of Valuations_in A st J,v |= Ant f holds
J,v |= q
let v be Element of Valuations_in A; ( J,v |= Ant f implies J,v |= q )
assume
J,v |= Ant f
; J,v |= q
then
J,v |= p '&' q
by A1, Def15;
hence
J,v |= q
by VALUAT_1:18; verum