>imtr

Theorem.

Arguments:

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

Hypotheses:

(psileftrightarrowtheta)
(phileftrightarrowchi)
(phitopsi)

Assertions:

(chitotheta)

Proof:

Hyp Ref Line Expr
Hypo1(psileftrightarrowtheta)
2(phileftrightarrowchi)
3(phitopsi)
2, 3brpi21<4(chitopsi)
1, 4brpi225(chitotheta)