Echo is an industrial-grade graph-rewrite simulation engine where state is a graph, time is a hash chain, and determinism is structurally enforced.
mindmap
root((Echo))
Structural Determinism
Parallel Rule Execution
Private Deltas
Canonical Merge
Inevitability
0-ULP Cross-Platform
BTreeMap Everything
Banned Non-determinism
Causal Substrate
WARP Graph (DPO)
Recursive Provenance
Hash-Locked Ticks
Native Replay
Time Travel Debugging
Counterfactual Forking
Worldline algebra
Geometric Lawfulness
Footprint Enforcement
Guarded Views
Transactional Commits
Echo does not solve the concurrency problem; it structurally prevents it from existing. Rules read from immutable snapshots and write to private deltas. Order-independence is a property of the bedrock, not a side-effect of synchronization.
A system is either deterministic or it is not. Echo bans the "approximately correct." Identical hashes across Linux, macOS, and Windows are the minimum bar. We ban non-deterministic sources (floats, system time, unseeded randomness) at the pre-commit and CI gates.
Independency is declared via footprints and enforced at runtime. Footprint guards reject undeclared access, and violations poison deltas. We do not trust the rule-author; we trust the runtime proof.
Deterministic replay is not a feature you turn on; it is how the engine works. Every tick is a cryptographic commit in a hash chain. Rewind, fork, and diff are inherent capabilities of the worldline algebra.
The engine is built for the systems engineer. Strict lints, panic-free paths (Mr. Clean), and comprehensive determinism drills (DIND) ensure that Echo remains a professional-grade bedrock for causal simulation.
The goal is inevitability. Every state transition is a provable consequence of its causal history.