im-true

Theorem.

Arguments:

phi (pr), psi (pr),

Assertions:

(phito(psileftrightarrow(phitopsi)))

Proof:

Hyp Ref Line Expr
ax11(psito(phitopsi))
1ax12(phito(psito(phitopsi)))
mpclosed3(phito((phitopsi)topsi))
2, 3>bid4(phito(psileftrightarrow(phitopsi)))