ceqi

Theorem.

Arguments:

x (sv), a (coll), b (coll),

Distinct variable conditions:

(x, a), (x, b),

Hypotheses:

((xina)leftrightarrow(xinb))

Assertions:

(aequivb)

Proof:

Hyp Ref Line Expr
Hypo1((xina)leftrightarrow(xinb))
1ax-gen2forallx((xina)leftrightarrow(xinb))
2df-equ3(aequivb)