If a given world (in a Kripke model (for intuitionistic logic)) forces neither A nor ¬A then there is some possible future world (accessible from the present one) in which A is forced true. In particular, if A eventually becomes forced somewhere along any possible time thread (towards the future), then the present world would force ¬¬A to be true, but if this does not happen there there exists some possible future world in which ¬A becomes true.

There is no evidence whatever of the white goat having existed in Wyoming.

He was crippled in one leg, which fact accounted for his moniker, for on the Road a lame man is a gimpy; even as a one-armed man is a wingy.

Your shoestring is untied.