About

Coverage you can inspect.

Segmentspan combines closed spans along one line, preserving every real gap and listing every merged component.

A strip measurement or annotated axis can contain overlapping ranges. Adding raw lengths counts overlap repeatedly; using only earliest/latest endpoints can fill real gaps. This focused tool makes the actual union explicit, so you can inspect combined coverage alongside the separate raw sum.

A deliberate continuous model

Closed bounds, exact decimal comparison and retained isolated points are explicit choices. [3,3] has zero continuous length but is not an empty set. Touching segments merge; any positive accepted gap remains. The input is a small decimal-pair list, rather than a spreadsheet, SQL range expression or geometry file.

Raw sum minus union is multiplicity excess. It is neither a cutting-waste estimate nor generally the length covered at least twice. The triple-duplicate example makes the distinction visible.

Local and checkable

The browser uses scaled integers. Independent endpoint/midpoint membership fixtures and rational length checks test set coverage without copying the production sort-and-merge algorithm. Parser boundaries, stale-state handlers, pagination and static checks support the release. Actual browser and hosting evidence remain separate steps.

No signup, upload, payment or conversation is needed. This release includes no analytics, advertising or consent-platform loaders. Inputs remain in page memory; optional copying and local files stay under your control. Read privacy for hosting/email details or use contact with a small invented bug example. Exact arithmetic does not establish physical suitability or source-data accuracy.