Thus a lambda term is valid if and only if it can be obtained by repeated application of these three rules.

In many presentations, it is usual to identify alpha-equivalent lambda terms.

This only came about with the lambda term.

The lambda term for the determiner no is the following.

The lambda term for the (complex) determiner exactly three is the following.

If a lambda term contains no subterms of the form ((λv.

This is equivalent to the undecidability of the corresponding problems for lambda terms.

If on the other hand we use a lambda term specifically designed to be easy to distinguish from any pairing, then the input becomes delimited.

First we need to write our lambda terms in a particular notation using what is known as De Bruijn indices.

A closed lambda term is one in which all variables are bound, i.e. without any free variables.