ax6e

Theorem.

Arguments:

x (sv), phi (pr),

Assertions:

(existsxforallxphitophi)

Proof:

Hyp Ref Line Expr
df-ex1(existsxforallxphileftrightarrowlnotforallxlnotforallxphi)
ax62(lnotforallxlnotforallxphitophi)
1, 2brpi213(existsxforallxphitophi)