Editing Singularity theory (section)

==Other possible meanings==
The theory mentioned above does not directly relate to the concept of [[mathematical singularity]] as a value at which a function is not defined. For that, see for example [[isolated singularity]], [[essential singularity]], [[removable singularity]]. The [[monodromy]] theory of [[differential equation]]s, in the complex domain, around singularities, does however come into relation with the geometric theory. Roughly speaking, ''monodromy'' studies the way a [[covering map]] can degenerate, while ''singularity theory'' studies the way a ''manifold'' can degenerate; and these fields are linked.