<anabs>

Theorem.

Arguments:

phi (pr), psi (pr),

Assertions:

(((phiwedgepsi)wedgepsi)leftrightarrow(phiwedgepsi))

Proof:

Hyp Ref Line Expr
anass1(((phiwedgepsi)wedgepsi)leftrightarrow(phiwedge(psiwedgepsi)))
anidm2((psiwedgepsi)leftrightarrowpsi)
2bi.bldan>3((phiwedge(psiwedgepsi))leftrightarrow(phiwedgepsi))
1, 3bitr4(((phiwedgepsi)wedgepsi)leftrightarrow(phiwedgepsi))