brpi33<

Theorem.

Arguments:

phi (pr), psi (pr), chi (pr), theta (pr),

Hypotheses:

(thetaleftrightarrowchi)
(phito(psitochi))

Assertions:

(phito(psitotheta))

Proof:

Hyp Ref Line Expr
Hypo1(thetaleftrightarrowchi)
2(phito(psitochi))
1bi<3(chitotheta)
2, 3rpi334(phito(psitotheta))