siman<

Theorem.

Arguments:

phi (pr), psi (pr),

Assertions:

((phiwedgepsi)tophi)

Proof:

Hyp Ref Line Expr
df-an1((phiwedgepsi)leftrightarrowlnot(phitolnotpsi))
pm3.26im2(lnot(phitolnotpsi)tophi)
1, 2brpi213((phiwedgepsi)tophi)