# ifc-geometry curve instructions
Scope: Borrowed views and local semantic validation for IFC curve entities.
Follow the crate `../../AGENTS.md`. Read this directory's `PLAN.md` only for assigned
work under parent task(s) `GEOM-CURVE`. Record progress there.
## Owns
- line/polyline/conic/trimmed/composite/offset/B-spline views
- curve-specific WHERE-rule inputs
- trim/select semantics without graph construction
## Does not own
- tessellation or tolerance policy
- placement-chain resolution
- surface/solid lowering
## Growth map
`line.rs`, `polyline.rs`, `conic.rs`, `trimmed.rs`, `composite.rs`, `offset.rs`, `bspline.rs`. These source owners already compile as private scaffold modules. Replace a module's planned-owner marker with its first real contract and tests; do not add parallel placeholders.
Every source entity error cites EntityId/type/slot or rule. Add invalid, cycle,
and unsupported cases, not only happy paths.