let A be non empty set ; :: thesis: for v being Element of Valuations_in A
for p being Element of CQC-WFF
for J being interpretation of A holds (Valid (('not' p),J)) . v = 'not' ((Valid (p,J)) . v)

let v be Element of Valuations_in A; :: thesis: for p being Element of CQC-WFF
for J being interpretation of A holds (Valid (('not' p),J)) . v = 'not' ((Valid (p,J)) . v)

let p be Element of CQC-WFF ; :: thesis: for J being interpretation of A holds (Valid (('not' p),J)) . v = 'not' ((Valid (p,J)) . v)
let J be interpretation of A; :: thesis: (Valid (('not' p),J)) . v = 'not' ((Valid (p,J)) . v)
(Valid (('not' p),J)) . v = ('not' (Valid (p,J))) . v by Lm1;
hence (Valid (('not' p),J)) . v = 'not' ((Valid (p,J)) . v) by MARGREL1:def 20; :: thesis: verum