let A be non empty set ; :: thesis: for p being Element of CQC-WFF
for J being interpretation of A holds J |= (('not' p) => p) => p
let p be Element of CQC-WFF ; :: thesis: for J being interpretation of A holds J |= (('not' p) => p) => p
let J be interpretation of A; :: thesis: J |= (('not' p) => p) => p
let v be Element of Valuations_in A; :: according to VALUAT_1:def 8 :: thesis: J,v |= (('not' p) => p) => p
thus J,v |= (('not' p) => p) => p by Th46; :: thesis: verum