I've written a Lambda Calculus evaluator, available in the archives; it's based on the Spreadsheet app that comes with the Prime. The spreadsheet is used as a dictionary of Lambda Calculus terms (using De Brujin indices, instead of normal notation, for now) and simple identifiers. These identifiers are used to reference the lambda expression on the Symb page. The Symb page supports evaluating the application of one function to another (and then to a third, optionally).

Screenshots and instructions are included, as well as a variety of terms in the dictionary/spreadsheet. Church Numerals are recognized automatically.

Future versions will support standard notation, using De Brujin indices only behind-the-scenes, as well as free-form entry of terms to be evaluated.

If interested in this sort of thing, let me know your thoughts.

I see there's some interest in programming the HP Prime in this forum. I'll follow up with a description of this version of the application's code.

Screenshots and instructions are included, as well as a variety of terms in the dictionary/spreadsheet. Church Numerals are recognized automatically.

Future versions will support standard notation, using De Brujin indices only behind-the-scenes, as well as free-form entry of terms to be evaluated.

If interested in this sort of thing, let me know your thoughts.

I see there's some interest in programming the HP Prime in this forum. I'll follow up with a description of this version of the application's code.