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src/doc/API.md

+Inox API
+========
+
+Trees
+-----
+
+Extendability is core to the design of the Inox AST (Abstract Syntax Tree).
+The [Trees](/src/main/scala/inox/ast/Trees.scala) trait can be extended with
+new constructs and provide useful override points to enable extensions with
+new features. See [Stainless](https://githum.com/epfl-lara/stainless) for some
+concrete examples.
+
+Programs are constructed from
+1. [Expressions](/src/main/scala/inox/ast/Expressions.scala)
+
+