.. toctree::
:numbered:
:maxdepth: 2
introduction
propositional_logic
natural_deduction_for_propositional_logic
propositional_logic_in_lean
classical_reasoning
semantics_of_propositional_logic
first_order_logic
natural_deduction_for_first_order_logic
first_order_logic_in_lean
semantics_of_first_order_logic
sets
sets_in_lean
relations
relations_in_lean
functions
functions_in_lean
the_natural_numbers_and_induction
the_natural_numbers_and_induction_in_lean
elementary_number_theory
combinatorics
the_real_numbers
the_infinite
axiomatic_foundations
nd_quickref