Full Idea
An intuitionist typically retains bivalence, but rejects the law of excluded middle.
Gist of Idea
Intuitionists typically retain bivalence but reject the law of excluded middle
Source
Michèle Friend (Introducing the Philosophy of Mathematics [2007], 5.2)
Book Reference
Friend,Michèle: 'Introducing the Philosophy of Mathematics' [Acumen 2007], p.106
A Reaction
The idea would be to say that only T and F are available as truth-values, but failing to be T does not ensure being F, but merely not-T. 'Unproven' is not-T, but may not be F.