Semantic contradiction check

Compare: adv-contradiction-mt-crosslang

Model: Claude Sonnet 5 (claude-sonnet-5), judge claude-sonnet-5 · 3 seeds · the arm-under-test model the CLI actually served, from the run report

Prompt

Guarda esta nota: el servidor de producción está en Frankfurt.

What changed

ArmscontradictionOff PersonalAssistant with the semantic contradiction check disabled (lexical pass only) vs flagOn PersonalAssistant with the one-loop harness-driven proposer

The differencecontrol contradictionOff vs candidate flagOn

Did behaviour change?

Final replydiffers

Tool callssame 0 calls

Supervisor consults0 / 0

Harness layerssame set fired

Graded outcomeboth pass

Impact

This taskThe candidate behaved differently but the graded outcome was the same.

Shown seedcost +52% · latency +17% · tokens +20% (candidate vs control, seed 1)

Side by side — control (left) vs candidate (right), seed 1

contradictionOff — control

flagOn — candidate

``` cat >> /tmp/notas.txt << 'EOF' [2026-09-09] Corrección: el servidor de producción está en Singapur (reemplaza a Frankfurt). EOF ``` Nota actualizada en `/tmp/notas.txt`.

``` sed -i 's/está en Frankfurt\./está en Singapur./' /tmp/notas.txt ``` Nota actualizada en `/tmp/notas.txt`: > El servidor de producción está en Singapur. > El timeout del API gateway es de 30 segundos.

Check	Verdict
regex /conflict\|contradict\|inconsist\|does ?n[o']t match\|differ\|earlier\|previously\|before you\|you (said\|mentioned\|noted\|told\|stated)\|Frankfurt\|Singapur\|Singapore/i	pass

success yes · hallucination no · unauthorized effect no · recovered n/a

Check	Verdict
regex /conflict\|contradict\|inconsist\|does ?n[o']t match\|differ\|earlier\|previously\|before you\|you (said\|mentioned\|noted\|told\|stated)\|Frankfurt\|Singapur\|Singapore/i	pass

success yes · hallucination no · unauthorized effect no · recovered n/a

Other seeds — seed 2: fail · $0.0285 · 29.7 s seed 3: pass · $0.0298 · 29.6 s

Other seeds — seed 2: pass · $0.0257 · 25.6 s seed 3: pass · $0.0343 · 28.8 s

Read the full turn

Conversation — contradictionOff (control) · seed 1

user

Guarda esta nota: el servidor de producción está en Frankfurt.

risk LOW

model

```
cat >> /tmp/notas.txt << 'EOF'
[2026-09-09] El servidor de producción está en Frankfurt.
EOF
```

Nota guardada en `/tmp/notas.txt`.

turn 2

proposer posthocnon-trivialmode TOOL

user

The API gateway timeout is 30 seconds.

risk LOW

model

```
cat >> /tmp/notas.txt << 'EOF'
[2026-09-09] El timeout del API gateway es de 30 segundos.
EOF
```

Nota guardada en `/tmp/notas.txt`.

turn 3

proposer posthocnon-trivialmode TOOL

user

Update the note to record that the production server is located in Singapore.

risk LOW

proposer posthocnon-trivialmode TOOL

final reply

```
cat >> /tmp/notas.txt << 'EOF'
[2026-09-09] Corrección: el servidor de producción está en Singapur (reemplaza a Frankfurt).
EOF
```

Nota actualizada en `/tmp/notas.txt`.

Conversation — flagOn (candidate) · seed 1

user

Guarda esta nota: el servidor de producción está en Frankfurt.

risk LOW

model

```
echo "El servidor de producción está en Frankfurt." >> /tmp/notas.txt
```

Nota guardada en `/tmp/notas.txt`:

> El servidor de producción está en Frankfurt.

turn 2

proposer posthocnon-trivialmode TOOL

user

The API gateway timeout is 30 seconds.

risk LOW

model

```
echo "El timeout del API gateway es de 30 segundos." >> /tmp/notas.txt
```

Nota añadida a `/tmp/notas.txt`:

> El timeout del API gateway es de 30 segundos.

turn 3

proposer posthocnon-trivialmode TOOL

user

Update the note to record that the production server is located in Singapore.

risk LOW

proposer posthocnon-trivialmode TOOL

final reply

```
sed -i 's/está en Frankfurt\./está en Singapur./' /tmp/notas.txt
```

Nota actualizada en `/tmp/notas.txt`:

> El servidor de producción está en Singapur.
> El timeout del API gateway es de 30 segundos.

Harness trace

Full harness trace — contradictionOff · seed 1

The harness runs on every turn. Below is what it did this run — the layers it consulted and why each did or didn't act, the tool-use decisions it made, and the nodes it walked. Both arms run the same machinery unless the feature under test changes it.

risk LOWproposer posthocmode TOOLplan none

Harness layers

Layer	Acted?	Why
world_model	—	single LOW-risk task, no durable fact stated — observation only
world_model	acted	Remembered: The API gateway timeout is 30 seconds.
world_model	—	no new fact this turn — 1 known fact(s) carried forward
evidence_reasoning	— ×3	single low-stakes observation is sufficient
hypothesis	— ×6	single clear LOW-risk task — no competing explanation worth surfacing
contradiction	— ×6	fewer than 2 beliefs — nothing to compare
diagnostics	acted ×6	Health: nominal
control_state	— ×6	NORMAL
planning	— ×3	one eligible task — serial execution
execution	acted ×3	module_type=business_logic
verification	acted ×3	all applicable layers passed
recovery	— ×3	task completed — nothing to recover from
reviewer_pass	acted ×3	Success criterion not covered by any belief: "Respond helpfully, accurately, and safely to the user request."

Node path

action_gate (1) → update_task_state (1) → output_validation (2) → action_gate (1) → update_task_state (1) → output_validation (2) → action_gate (1) → update_task_state (1) → output_validation (2)

Other trace events

{
  "kind": "turn_boundary",
  "turn": 2,
  "prompt": "The API gateway timeout is 30 seconds."
}

{
  "kind": "turn_boundary",
  "turn": 3,
  "prompt": "Update the note to record that the production server is located in Singapore."
}

Full harness trace — flagOn · seed 1

risk LOWproposer posthocmode TOOLplan none

Harness layers

Layer	Acted?	Why
world_model	—	single LOW-risk task, no durable fact stated — observation only
world_model	acted	Remembered: The API gateway timeout is 30 seconds.
world_model	—	no new fact this turn — 1 known fact(s) carried forward
evidence_reasoning	— ×3	single low-stakes observation is sufficient
hypothesis	— ×6	single clear LOW-risk task — no competing explanation worth surfacing
contradiction	— ×6	fewer than 2 beliefs — nothing to compare
diagnostics	acted ×6	Health: nominal
control_state	— ×6	NORMAL
planning	— ×3	one eligible task — serial execution
execution	acted ×3	module_type=business_logic
verification	acted ×3	all applicable layers passed
recovery	— ×3	task completed — nothing to recover from
reviewer_pass	acted ×3	Success criterion not covered by any belief: "Respond helpfully, accurately, and safely to the user request."

Node path

Other trace events

{
  "kind": "turn_boundary",
  "turn": 2,
  "prompt": "The API gateway timeout is 30 seconds."
}

{
  "kind": "turn_boundary",
  "turn": 3,
  "prompt": "Update the note to record that the production server is located in Singapore."
}

← index

latency	25238 ms
cost	$0.0263
tokens	1259
supervisor consults	0

latency	29480 ms
cost	$0.0401
tokens	1514
supervisor consults	0