banc>

Theorem.

Arguments:

phi (pr), psi (pr),

Assertions:

((phitopsi)leftrightarrow(phito(psiwedgephi)))

Proof:

Hyp Ref Line Expr
anc>1((phitopsi)to(phito(psiwedgephi)))
siman<2((psiwedgephi)topsi)
2syl<3((phito(psiwedgephi))to(phitopsi))
1, 3>bii4((phitopsi)leftrightarrow(phito(psiwedgephi)))