logic
=====

Logical constructions and theorems, beyond what has already been
declared in init.datatypes and init.logic. 

The subfolder logic.axioms declares additional axioms. The command
`import logic` does not import any axioms by default.

* [connectives](connectives.lean) : the propositional connectives
* [eq](eq.lean) : additional theorems for equality and disequality
* [cast](cast.lean) : casts and heterogeneous equality
* [quantifiers](quantifiers.lean) : existential and universal quantifiers
* [identities](identities.lean) : some useful identities
* [instances](instances.lean) : class instances for eq and iff
* [subsingleton](subsingleton.lean)
* [default](default.lean)

Subfolders:

* [axioms](axioms/axioms.md) : additional axioms
* [examples](examples/examples.md)