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 \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 \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 \imp A in F
let F be PC-theory of L; :: thesis: for A being Formula of L holds A \imp A in F
let A be Formula of L; :: thesis: A \imp A in F
A1: (A \imp ((A \imp A) \imp A)) \imp ((A \imp (A \imp A)) \imp (A \imp A)) in F by Def38;
A2: A \imp ((A \imp A) \imp A) in F by Def38;
A3: (A \imp (A \imp A)) \imp (A \imp A) in F by A1, A2, Def38;
A4: A \imp (A \imp A) in F by Def38;
thus A \imp A in F by A3, A4, Def38; :: thesis: verum