im.bldan<>

Theorem.

Arguments:

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

Hypotheses:

(chitotheta)
(phitopsi)

Assertions:

((phiwedgechi)to(psiwedgetheta))

Proof:

Hyp Ref Line Expr
Hypo1(chitotheta)
2(phitopsi)
siman<3((phiwedgechi)tophi)
2, 3syl4((phiwedgechi)topsi)
siman>5((phiwedgechi)tochi)
1, 5syl6((phiwedgechi)totheta)
4, 6jca7((phiwedgechi)to(psiwedgetheta))