---

title: 'Operators must include goal_fail, which mutates: Replaces a body goal with fail.' status: open text_ref: readme:README.md#L122 tags:

• strict-modeling
• confidence:0.90
• confidence-band:high
• provenance:readme-readme-md-l122
• lane:strict

semantic_text: 'Operators must include goal_fail, which mutates: Replaces a body goal with fail.' logic_claims:

• CLAIM-167FB02AB48BA73D

semantic_clauses:

• 'Operators must include goal_fail, which mutates: Replaces a body goal with fail.'

semantic_inventory_version: kibi.semantic-inventory.v1 semantic_source_field: semantic_text semantic_source_hash: a1ba3bf9d1103ead1c5849c250248b4faaad1dcada55afa1fbc0c54f11f4dfe9 semantic_inventory:

• claim_key: CLAIM-167FB02AB48BA73D claim_text: 'Operators must include goal_fail, which mutates: Replaces a body goal with fail' role: normative status: modeled span: start: 0 end: 81 origin: kind: import ref: readme:README.md#L122 recorded_at: '2026-10-29T16:05:28.762Z' firmness: firm required_evidence: asserted id: REQ-AUTO-653372986C2F6926 type: req --- Operators must include goal_fail, which mutates: Replaces a body goal with fail.

Source

| goal_fail | Replaces a body goal with fail | p :- q, r. to p :- q, fail. |

Source: Mutalog README - README.md#L122