metadata:
version: "1.0.0"
author: "Sovereign AI Stack"
description: "Checkpoint contract for simulation state persistence and recovery"
crate: "simular"
references:
- "Chen et al. (2016) Training Deep Nets with Sublinear Memory Cost, arXiv:1604.06174"
- "Jain et al. (2020) Checkmate: Breaking the Memory Wall with Optimal Tensor Rematerialization"
equations:
checkpoint_roundtrip:
formula: "deserialize(serialize(state)) == state"
domain: "state in SimulationState"
invariants:
- "Serialization is lossless for all state components"
- "Deserialized state produces identical simulation continuation"
checkpoint_size:
formula: "size(checkpoint) = Sum_{p in params} sizeof(p) + metadata_overhead"
domain: "params in Vec<Parameter>"
invariants:
- "Checkpoint size bounded by model parameter count"
- "Metadata overhead is O(1) per checkpoint"
checkpoint_interval:
formula: "checkpoint_at(step) = (step % interval == 0) || is_best(metric)"
domain: "step >= 0, interval >= 1"
invariants:
- "Checkpoints created at regular intervals"
- "Best model always checkpointed regardless of interval"
proof_obligations:
- type: invariant
property: "Roundtrip fidelity"
formal: "deserialize(serialize(state)) == state for all valid states"
applies_to: all
- type: bound
property: "Checkpoint size bounded"
formal: "size(checkpoint) <= max_checkpoint_size"
applies_to: all
- type: invariant
property: "Best model always saved"
formal: "is_best(metric) implies checkpoint exists for that step"
applies_to: all
- type: invariant
property: "Checkpoint file integrity"
formal: "checksum(read(path)) == stored_checksum"
applies_to: all
falsification_tests:
- id: FALSIFY-CKPT-001
rule: "Roundtrip fidelity"
test: "test_streaming_checkpoint_roundtrip"
prediction: "verified"
if_fails: "State corruption during serialization"
- id: FALSIFY-CKPT-002
rule: "Size bounded"
test: "test_checkpoint_compressed_size"
prediction: "verified"
if_fails: "Checkpoint grows unboundedly"
- id: FALSIFY-CKPT-003
rule: "Best model saved"
test: "test_checkpoint_manager"
prediction: "verified"
if_fails: "Best model checkpoint missed"
- id: FALSIFY-CKPT-004
rule: "File integrity"
test: "test_checkpoint_integrity_check"
prediction: "verified"
if_fails: "Corrupted checkpoint not detected"
kani_harnesses:
- id: KANI-CKPT-001
obligation: PO-CKPT-001
property: "Roundtrip fidelity"
bound: 8
strategy: bounded_int
harness: verify_checkpoint_roundtrip
- id: KANI-CKPT-002
obligation: PO-CKPT-002
property: "Size bound"
bound: 8
strategy: bounded_int
harness: verify_checkpoint_size
qa_gate:
id: QA-CHECKPOINT
name: "checkpoint contract"
min_coverage: 0.90
max_complexity: 20
required_tests:
- test_streaming_checkpoint_roundtrip
- test_checkpoint_compressed_size
- test_checkpoint_manager
- test_checkpoint_integrity_check