👉 In mathematics, a coessential vector space is a vector space over a field F with the property that every element of the space is a linear combination of finitely many elements from another vector space. This concept was introduced by William Rowan Hamilton in his work "On the Theory of Numbers" (1850) and it has applications in algebra, geometry, and number theory. In coessential spaces, each element x of the vector space is a linear combination of finitely many