let n be non empty Nat; :: thesis: for S being non empty non void n PC-correct PCLangSignature
for L being language MSAlgebra over S
for F being PC-theory of L
for A being Formula of L holds (A \or A) \imp A in F
let S be non empty non void n PC-correct PCLangSignature ; :: thesis: for L being language MSAlgebra over S
for F being PC-theory of L
for A being Formula of L holds (A \or A) \imp A in F
let L be language MSAlgebra over S; :: thesis: for F being PC-theory of L
for A being Formula of L holds (A \or A) \imp A in F
let F be PC-theory of L; :: thesis: for A being Formula of L holds (A \or A) \imp A in F
let A be Formula of L; :: thesis: (A \or A) \imp A in F
A1: (A \imp A) \imp ((A \imp A) \imp ((A \or A) \imp A)) in F by Def38;
A2: A \imp A in F by Th34;
then (A \imp A) \imp ((A \or A) \imp A) in F by A1, Def38;
hence (A \or A) \imp A in F by A2, Def38; :: thesis: verum