922 B
922 B
logic
Logical constructions and theorems, beyond what has already been declared in init.datatypes and init.logic.
The command import logic does not import any axioms by default.
- connectives : the propositional connectives
- eq : additional theorems for equality and disequality
- cast : casts and heterogeneous equality
- quantifiers : existential and universal quantifiers
- identities : some useful identities
- instances : class instances for eq and iff
- subsingleton
- default
The file choice.lean declares a choice axiom, and uses it to
prove the excluded middle, propositional completeness, axiom of
choice, and prove that the decidable class is trivial when the
choice axiom is assumed.
Subfolders: