# node > Every PAG keyword record, with what grounds it and how it is checked. Page: Ontology · Grammar Canonical: https://banes-lab.com/ontology/grammar#pag-keywords-node Listed in [Ontology · Grammar](https://banes-lab.com/api/pages/ontology/grammar.md), after [invariant](https://banes-lab.com/ontology/grammar/pag-keywords-invariant.md) and before [semantic_operation](https://banes-lab.com/ontology/grammar/pag-keywords-semantic-operation.md). Every PAG keyword record, with what grounds it and how it is checked. ### NODE Details Meaning A node header · the unit of a document, one decision, one gate Example # NODE — [ · · · yields: ] Grounds [loop:derivation-loop](https://banes-lab.com/ontology/reasoning/reasoning-loop-derivation-loop.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### CONTRACT Details Meaning A node's contract · input, transform, constraints, output, handoff Example CONTRACT: Grounds [loop:derivation-loop](https://banes-lab.com/ontology/reasoning/reasoning-loop-derivation-loop.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### YIELDS Details Meaning The shape a node's decision resolves to Example yields: Grounds [axis:formalization](https://banes-lab.com/records/reasoning/axis-formalization.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### GENESIS Details Meaning The substrate stage the node's artifact comes to be at · phase order follows it Example @genesis: Grounds [substrate-node:existence](https://banes-lab.com/records/reasoning/substrate-node-existence.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### PRESERVES Details Meaning The distinctions a transform keeps · a lowering names what a later check needs Example preserves: , Grounds [invariant:epi-preserved-distinction](https://banes-lab.com/records/reasoning/invariant-epi-preserved-distinction.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### OUTPUT_CONTRACT Details Meaning The one record the next node reads, as an assignment Example # OUTPUT CONTRACT Grounds [axis:formalization](https://banes-lab.com/records/reasoning/axis-formalization.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### LIMIT Details Meaning A declared limit · stated where a reader would otherwise assume the opposite Example LIMIT : "" Grounds [substrate-node:constraint](https://banes-lab.com/records/reasoning/substrate-node-constraint.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ### SLOT Details Meaning A slot's state · resolved, absent or deferred, declared by the adapter Example SLOT {.}: RESOLVED | ABSENT | DEFERRED Grounds [node:for-absence](https://banes-lab.com/records/reasoning/node-for-absence.md) How it is checked Checked by a structured-document validator that parses each document against the grammar and reports every defect by its shape Population Every agent and template document the validator walks, and every occurrence of the keyword in them Freshness A verdict stands until the grammar data or a document that uses the keyword changes Refusal The validation stage fails the gate on any defect code, so a document with a malformed keyword does not ship Observation None, because a keyword is static text in a document, and nothing observes it while a run executes Evidence Watched to fire and to accept: a suite plants a retired head in a real template and validates every agent and template on disk clean Authoritative side The grammar data, which every keyword in a document conforms to Depends on Not answered Shape it refuses Not answered ## Links to - [The derivation loop](https://banes-lab.com/ontology/reasoning/reasoning-loop-derivation-loop.md) - [Formalization](https://banes-lab.com/records/reasoning/axis-formalization.md) - [Existence](https://banes-lab.com/records/reasoning/substrate-node-existence.md) - [Preserved Distinction](https://banes-lab.com/records/reasoning/invariant-epi-preserved-distinction.md) - [Constraint](https://banes-lab.com/records/reasoning/substrate-node-constraint.md) - [Absence](https://banes-lab.com/records/reasoning/node-for-absence.md)