Definition
Plain language
Checking something at the door before letting it in, rather than cleaning up problems after the fact.
As stated in the literature
A systems principle of gating what may enter a shared resource; in DeLM, a verifier fact-checks every note against its cited evidence before it is written to shared context, stopping error propagation at write time rather than at answer time.
Why it matters: It stops bad inputs from corrupting a shared resource at the moment they arrive, which is far cheaper than tracing and undoing the damage afterward.
For example, a bouncer checks each guest's ID at the entrance instead of letting everyone in and then trying to find the troublemakers later.
Heard on the show
“The middle layer is admission control.”Episode 016 — Why Your Coding Agent Stalls While the GPU Runs Hot