SYSTEM: Education OS
MODULE: UK Verification OS — GCSE OS
SCOPE: GCSE verification gate (Upper Secondary)
ZOOM LINK: Z6 (Nation gate spec) ↔ Z5 (City execution) ↔ Z0 (student execution)
REFERENCE: CivOS (Phase P0–P3)
PRIMARY PURPOSE:
  Convert multi-year learning into timed, verifiable outcomes
  while preserving transfer reliability and reducing tail failure.

GATE: GCSE Verification Gate
FUNCTION:
  Verify:
    - subject competence
    - transfer under wrapper variation
    - timed execution reliability
    - sustained performance across papers
OUTPUT:
  pathways + post-16 routing (A-Level / vocational routes)
FAILURE COST:
  restricted pathways + delayed skill regeneration

P0 (Fragile):
  Can do familiar questions with heavy cues; collapses under timed sets.
P1 (Unstable):
  Can solve some topics; performance volatile; wrapper changes break execution.
P2 (Stable):
  Can solve core topics reliably; timed stability improving; transfer mostly works.
P3 (Reliable):
  Executes across mixed papers under time; recovers from mistakes; transfer strong.

FAILURE_MODES (GCSE):
  G-F01: Early language drift persists (comprehension decoding failure)
  G-F02: Practice without model (GF2)
  G-F03: Option-selection misrouting (wrong subject set / mismatched difficulty)
  G-F04: Divergence masking (school variance hides tails until ramp)
  G-F05: Transition shock amplification into exam ramp (GF5→GF3)
  G-F06: Timed execution collapse (GF6)
  G-F07: Transfer failure under novelty (GF9)
  G-F08: Late repair trap (GF7)
  G-F09: Continuity fragmentation (attendance/churn resets loops) (GF11)
  G-F10: Narrative substitution (no sensors, no loops) (GF10)

PHASE SENSORS (GLOBAL):
  P-S1 retrieval reliability
  P-S2 error histogram (concept/execution/attention)
  P-S3 time-to-solve distribution
  P-S4 transfer (new wrapper same concept)
  P-S5 timed stability variance

GCSE SYSTEM SENSORS:
  GCSE-S1: pre-ramp tail thickness (P0 proportion before Year 10/11 ramp)
  GCSE-S2: repair latency distribution (drift→stability timing)
  GCSE-S3: timed vs untimed gap (execution collapse indicator)
  GCSE-S4: transfer gap under wrapper variation
  GCSE-S5: option-risk index (subject choices vs readiness)
  GCSE-S6: divergence spread (inter-school variance; tails by cluster)

REPAIR MECHANISMS (MAP TO GR*):
  GR5 Language-Base Loop        → for G-F01
  GR1 Buffer Build Loop         → for G-F02/G-F07
  GR3 Transfer Loop             → for G-F07
  GR4 Time-Pressure Loop        → for G-F06
  GR2 Error-Log Loop            → for G-F06/G-F08
  GR6 Continuity Loop           → for G-F09
  GR8 Early-Warning Thresholds  → for G-F08 (pre-ramp triggers)
  GR7 Tail Visibility Protocol  → for G-F04 (system-level)
  GR9 Cluster Targeting         → for G-F04/G-F06 (system-level)
  GR10 Standardised Protocols   → for turnover/divergence resilience

EARLY WARNING (GCSE):
  Trigger repair immediately if any are true:
    - P-S5 volatility high across timed sets (unstable execution)
    - P-S4 transfer fails on wrapper variants
    - GCSE-S3 timed gap widening
    - GCSE-S2 repair latency exceeds remaining time to ramp

FAILURE TRACE (GCSE):
  GF1 language drift →
  GF2 practice without model →
  GF9 novelty collapse →
  GF6 timed execution collapse →
  GF7 late repair trap →
  gate failure at GCSE
REPAIR TRACE (GCSE):
  GR5 language base →
  GR1 buffer build →
  GR3 transfer audits →
  GR4 timed micro-sets + recovery →
  GR2 error-log closure →
  P3 reliability across full papers

GCSE SUCCESS (OS DEFINITION):
  Not “good grades”.
  It is:
    - stable timed execution
    - strong transfer under wrapper variation
    - low volatility across papers
    - repair latency short enough to stay ahead of ramps

SYSTEM: Education OS
MODULE: UK Verification OS — A-Level OS
SCOPE: Post-16 verification gate (A-Level)
ZOOM LINK: Z6 ↔ Z5 ↔ Z0
REFERENCE: CivOS (Phase P0–P3)
PRIMARY PURPOSE:
  Verify high-depth capability under abstraction,
  with strong transfer, proof/argument stability,
  and sustained performance under time.

GATE: A-Level Verification Gate
FUNCTION:
  Verify:
    - abstraction handling (depth not breadth)
    - multi-step reasoning stability
    - proof/argument quality (where relevant)
    - timed execution across long papers
OUTPUT:
  university entry routing + scholarship/placement signals
FAILURE COST:
  pathway restriction + remediation burden + confidence collapse

P0:
  Topic fragments; cannot sustain multi-step chains.
P1:
  Can do parts; collapses when papers mix topics or when questions are novel.
P2:
  Stable on core; can complete chains; minor volatility under time.
P3:
  Reliable across full papers; recovers from errors; transfer strong; low volatility.

FAILURE_MODES (A-LEVEL):
  A-F01: Weak pre-requisites from GCSE masked by grades (silent gaps)
  A-F02: Abstraction jump failure (cannot build/maintain reasoning chains)
  A-F03: Transfer collapse under novel synthesis questions (GF9)
  A-F04: Timed endurance collapse (long-paper fatigue → error spikes)
  A-F05: Late repair trap (starts only near exam season) (GF7)
  A-F06: Overload from multi-subject coordination (self-scheduling failure)
  A-F07: Proof/argument instability (structure & clarity fail) (subject-dependent)
  A-F08: Narrative substitution (no sensor loops) (GF10)

A-LEVEL CORE SENSORS:
  AL-S1: chain-length stability (max reliable multi-step length)
  AL-S2: synthesis transfer score (novel mixed-topic wrapper success rate)
  AL-S3: timed endurance stability (late-paper error density vs early-paper)
  AL-S4: volatility across full papers (P-S5)
  AL-S5: repair latency vs exam horizon (can repair close enough?)
  AL-S6: self-scheduling stability (weekly completion vs plan variance)

REPAIR MECHANISMS (MAP TO GR*):
  GR1 Buffer Build Loop         → rebuild prerequisite spine + depth
  GR3 Transfer Loop             → synthesis + novel wrappers
  GR4 Time-Pressure Loop        → long-paper pacing + recovery protocol
  GR2 Error-Log Loop            → remove recurring chain breaks
  GR6 Continuity Loop           → routine stabilisation for long horizon
  GR8 Early-Warning Thresholds  → trigger repair before exam season
  GR11 Pressure-Safety Schedule → prevent burnout tail in intense tracks
  GR10 Standardised Protocols   → consistent loops across teachers/tutors

EARLY WARNING (A-LEVEL):
  Trigger repair if any are true:
    - AL-S1 chain-length collapses under time
    - AL-S2 synthesis transfer < threshold
    - AL-S3 late-paper error density spikes
    - AL-S5 repair latency exceeds remaining horizon
    - AL-S6 weekly plan variance high (self-scheduling drift)

FAILURE TRACE (A-LEVEL):
  silent prerequisite gaps (A-F01) →
  abstraction jump failure (A-F02) →
  synthesis novelty collapse (A-F03) →
  timed endurance collapse (A-F04) →
  late repair trap (A-F05) →
  gate failure
REPAIR TRACE (A-LEVEL):
  GR1 depth spine rebuild →
  GR3 synthesis transfer audits →
  GR4 long-paper timed stability →
  GR2 chain-break error closure →
  GR6 continuity + GR11 pressure safety →
  P3 reliability across full papers

SYSTEM: UK Verification OS
INDEX: UK Verification Gates Directory
CONTENTS:
  - GCSE OS (Verification under divergence + option routing)
  - A-Level OS (Verification under abstraction + autonomy)
PORTS:
  - W2: GBR Nation Aggregate
  - W1: GBR-LON City instance
  - W3: Comparatives (SG↔LON etc.)
  - W4: GF failure library
  - W5: GR repair library