\begin{definition}[Definition:Scheme]
Let $\struct {X, \OO_X}$ be a locally ringed space.
Let $\struct {X, \OO_X}$ be such that:
:every point $x \in X$ has an open neighborhood $U_x$ such that:
::the restriction of $\struct {X, \OO_X}$ to $U_x$ is an '''affine scheme'''.
Then $\struct {X, \OO_X}$ is called a '''scheme'''.
\end{definition}