{0 Default calculus} This representation is the fourth in the compilation chain (see {{: index.html#architecture} Architecture}). Its main difference with the previous {{: desugared.html} desugared representation} is that scopes have been lowered into regular functions, and enums and structs have been lowered to sum and product types. The default calculus can be later compiled to a {{: lcalc.html} lambda calculus}. The module describing the abstract syntax tree is: {!modules: Dcalc.Ast} Printing helpers can be found in {!module: Dcalc.Print}. This intermediate representation corresponds to the default calculus presented in the {{: https://arxiv.org/abs/2103.03198} Catala formalization}. {1 Typing } Related modules: {!modules: Dcalc.Typing} This representation is where the typing is performed. Indeed, {!module: Dcalc.Typing} implements the classical {{: https://en.wikipedia.org/wiki/Hindley%E2%80%93Milner_type_system} W algorithm} corresponding to a Hindley-Milner type system, without type constraints. {1 Interpreter} Related modules: {!modules: Dcalc.Interpreter} Since this representation is currently the last of the compilation chain, an {!module: Dcalc.Interpreter} module is provided to match the execution semantics of the default calculus. Later, translations to a regular lambda calculus and/or a simple imperative language are bound to be added.