@@ 1305,7 1305,8 @@ store. To instruct the daemon to perform a build action, users actually
provide it with a @dfn{derivation}. A derivation is a low-level
representation of the build actions to be taken, and the environment in
which they should occur---derivations are to package definitions what
-assembly is to C programs.
+assembly is to C programs. The term ``derivation'' comes from the fact
+that build results @emph{derive} from them.
This chapter describes all these APIs in turn, starting from high-level
package definitions.