From e17c03bd8ce5b051ce06e123d3ce65d6086591be Mon Sep 17 00:00:00 2001 From: Jim Pryor Date: Tue, 5 Oct 2010 07:54:41 -0400 Subject: [PATCH] evaluator: note on variable-naming rules Signed-off-by: Jim Pryor --- lambda_evaluator.mdwn | 1 + 1 file changed, 1 insertion(+) diff --git a/lambda_evaluator.mdwn b/lambda_evaluator.mdwn index c9e21644..78fc60cb 100644 --- a/lambda_evaluator.mdwn +++ b/lambda_evaluator.mdwn @@ -21,6 +21,7 @@ Blank lines are fine. *Constants*: The combinators `S`, `K`, `I`, `C`, `B`, `W`, `T`, `M` (aka ω) and `L` are pre-defined to their standard values. Also, integers will automatically be converted to Church numerals. (`0` is `\s z. z`, `1` is `\s z. s z`, and so on.) +*Variables*: Variables must start with a letter and can continue with any sequence of letters, numbers, `_`, `-`, or `/`. They may optionally end with `?` or `!`. When the evaluator does alpha-conversion, it may change `x` into `x'` or `x''` and so on. But you should not attempt to use primed variable names yourself.