exan<vv

Theorem.

Arguments:

x (sv), y (sv), phi (pr), psi (pr),

Distinct variable conditions:

(x, phi), (y, phi),

Assertions:

(existsxexistsy(phiwedgepsi)leftrightarrow(phiwedgeexistsxexistsypsi))

Proof:

Hyp Ref Line Expr
exdistr1(existsxexistsy(phiwedgepsi)leftrightarrowexistsx(phiwedgeexistsypsi))
exan<2(existsx(phiwedgeexistsypsi)leftrightarrow(phiwedgeexistsxexistsypsi))
1, 2bitr3(existsxexistsy(phiwedgepsi)leftrightarrow(phiwedgeexistsxexistsypsi))