# Formal system

From apm

## External links

- Experiencing systems as a puzzle game - very good! http://incredible.pm/

### Wikipedia

- Formal_system, Formal_language, Formal_grammar (Abstract_syntax_tree, Backus–Naur_form)
- Rewriting and Substitution, Explicit_substitution
- Chomsky_hierarchy

- Boolean_algebra (De Morgan's laws, Karnaugh_map)
- Propositional_calculus, Second-order_propositional_logic (Second-order_logic), Higher-order_logic

- Intuitionistic_logic, Intuitionistic_type_theory, Curry–Howard_correspondence
- Untyped_lambda_calculus, Simply_typed_lambda_calculus, Typed_lambda_calculus, System_F
- Evaluation_strategy, De_Bruijn_index (or better alternative)
- Lambda_cube, Dependent_type

- Foundations_of_mathematics, Category_theory, Corecursion
- Categorical_logic Bicartesian_closed_category (Homotopy type theory, Lawvere theories)