For the parts of each edge of the source that are not coincident or overlapping with source-compatible figures, and the edge length is greater than the given dimension, a rectangle extending normally from the edge into the source figure by the given dimension plus a tiny extra is constructed. The test fails if this constructed rectangle is completely covered by source-compatible figures.
The ``tiny extra'' is one internal unit for Manhattan edges. An additional ``fudge factor'' is added for non-Manhattan edges to overcome roundoff error.
When importing Virtuoso technology data, the maxWidth constraint maps directly to this rule.