=== LOL Lambda ===

A lambda expression is written in the form:

  \(a : I) = ...

Examples:

  \(a : I) = a            identity function for propositions
  \(a : (I ~= I)) = a     identity function for one-dimensional propositions

This syntax is designed to be follow standard mathematical notation.
Standard mathematical notation for functions uses `f(a : I) = a`.
The `\` symbol is often associated with lambda expression in other languages.
Here it is used to signal an anonymous function, which is a lambda expression.
