sdd:PortCopy as claim

A sdd:Port is a named, grounded anchor on a sdd:Node's boundary — where an sdd:Edge attaches instead of the node's boundary generically. Ports are node-scoped flat names, addressable as node.port regardless of which sdd:Section declares them; duplicate port names anywhere within one node are an error (design spec §2). A port's identifying skolem elides the declaring section entirely (#d.p101.disch, not #d.p101.base.disch) while sdd:parent still points at the true declaring section — the elision is what keeps node.port addressing stable when sections restructure.Copy as claim

Every port has a sdd:direction — in, out, or io — and grounds through sdd:binds like a datum. Its sdd:anchor literal is always materialized, never left to a renderer: a computed cache of the port's border position, recomputed whenever the section layout changes.Copy as claim