ps-irr

Theorem.

Arguments:

a (obj),

Assertions:

lnot(alta)

Proof:

Hyp Ref Line Expr
nexmid1lnot((alea)wedgelnot(alea))
df<-alt32((alta)leftrightarrow((alea)wedgelnot(alea)))
1, 2bmto<3lnot(alta)