Such types are called "propositions" in univalent foundations. Vaccines may be "monovalent" (also called "univalent") or "multivalent" (also called "polyvalent"). For example, the first fundamental construction in univalent foundations is called iscontr. The concept of a univalent fibration was introduced by Voevodsky in early 2006. Isoxazolyl is the univalent radical derived from isoxazole. We have that formula 1 is univalent when formula 4. The development of univalent foundations is closely related to the development of homotopy type theory. He worked on a Coq library "UniMath" using univalent ideas. Species with a single charge are univalent (monovalent). The Koebe 1/4 theorem provides a related estimate in the case that "f" is univalent. In Bourbaki's terms, the corresponding theory is "univalent". Isobornyl is the univalent radical CH that is derived from isoborneol. These equivalences provide alternative formulas for univalent relations (formula 5), and total relations (formula 6). The univalent perchlorate ion () has valence 1.