  Mathematical knowledge is a central component in science, engineering, and
technology (documentation). Most of it is represented informally, and -- in
contrast to published research mathematics -- subject to continual change.
Unfortunately, machine support for change management has either been very
coarse grained and thus barely useful, or restricted to formal languages, where
automation is possible. In this paper, we report on an effort to extend change
management to collections of semi-formal documents which flexibly intermix
mathematical formulas and natural language and to integrate it into a semantic
publishing system for mathematical knowledge. We validate the long-standing
assumption that the semantic annotations in these flexiformal documents that
drive the machine-supported interaction with documents can support semantic
impact analyses at the same time. But in contrast to the fully formal setting,
where adaptations of impacted documents can be automated to some degree, the
flexiformal setting requires much more user interaction and thus a much tighter
integration into document management workflows.
