siman>

Theorem.

Arguments:

phi (pr), psi (pr),

Assertions:

((phiwedgepsi)topsi)

Proof:

Hyp Ref Line Expr
df-an1((phiwedgepsi)leftrightarrowlnot(phitolnotpsi))
pm3.27im2(lnot(phitolnotpsi)topsi)
1, 2brpi213((phiwedgepsi)topsi)