Workflow Reliability term
Invariant: meaning, examples, and expert terminology.
Captures rules that must remain true across every state and transition.
What it means
Plain meaning
Captures rules that must remain true across every state and transition.
Aliases
system rule, must always be true
People say / experts say
People usually say
- should never happen
- data mismatch
- broken state
- consistency
- safety
- invalid state
Experts usually say
Invariant, Assertion, Contract test, Transition table
When to use it
Use it when
Your rough ask sounds like: should never happen, data mismatch, broken state. The term gives your coding agent a clearer problem shape.
When not to use it
Do not use this term as a request for a quick screen fix. Use it when the system needs explicit state, rules, failures, or recovery behavior.
Copy-ready handoff phrase
Before and after examples
Prompt upgrade
Weak ask: Fix this should never happen flow.
Exact Terms ask: List the invariants this flow must preserve, then test each transition against them.
Handoff examples by use case
Architecture prompt
Audit this workflow for Invariant and related concerns: Assertion, Contract test, Transition table. Return states, rules, failure modes, and recovery behavior before code.
Implementation prompt
Implement Invariant for this app flow. Include data ownership, edge cases, fallback behavior, and acceptance tests.
Test prompt
Create tests that prove Invariant works across refresh, retry, back/next movement, partial failure, and return visits.
Common mistake
What goes wrong
Asking for code before defining states, transitions, persistence, and failure behavior.
Better move
Use Invariant with the related vocabulary trail: Assertion, Contract test, Transition table.
Related terms
Missing a better term?
Turn feedback into vocabulary
If this page almost names your problem but misses the exact term, send the rough phrase and the term you expected. Accepted feedback becomes a better trigger, explanation, comparison page, or new term.