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+# Check of modes correctness
+
+## Info
+
+https://blog.janestreet.com/oxidizing-ocaml-locality/
+https://blog.janestreet.com/oxidizing-ocaml-ownership/
+
+- **locality:** *global* (default) or *local* (value should not be passed out of context, can be allocated on stach)
+
+- **uniqueness:** *shared* (default), *unique* (used only once, consumed), *exclusive* (used only once in the same time)
+
+- **linearity:** *many* (default), *once* (result value can be used by caller only once), *separated* (result value can be used by caller only once in the same time)
+
+## Done
+
+- *unique* check +
+- *exclusive* check
+- *local* check
+- *once* check
+- *separated* check
+- type check (optional)
+
+## Examples
+
+- *unique:* let f (unique x) = x * x in f;; -> error