Unable to replicate the paper Fontana and Buss 1994 (https://link.springer.com/content/pdf/10.1007/BF02458289.pdf)

[julianzxue]

Unable to replicate the paper Fontana and Buss 1994 (https://link.springer.com/content/pdf/10.1007/BF02458289.pdf)

[ljedrz]

Thanks for the report! I can't check it out right now, but I'll do so soon 👍.

[julianzxue]

Thank you!!

…

On Thu., Feb. 9, 2023, 4:25 a.m. ljedrz, ***@***.***> wrote: Thanks for the report! I can't check it out right now, but I'll do so soon 👍. — Reply to this email directly, view it on GitHub <#47 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABCQGQNWDILYSBZKHBQRIOLWWSZW7ANCNFSM6AAAAAAUUXJDKI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[ljedrz]

Disclaimer: I haven't played with lambda calculus for a good while now, so please take this with a grain of salt 😃.

I think it's just the fact that you need to add some extra explicit parentheses, otherwise the parser will automatically fold/collapse some of the sub-expressions (as suggested by the results of your parsing); the following seems to do the trick:

let expr_a = parse(r#"\a. (a (\b. (\c. (c (\d. (\e. (e d)))))))"#, Classic).unwrap();
let expr_b = parse(r#"\a. (a (\b. (\c. (c b))))"#, Classic).unwrap();

assert_eq!(beta(app(expr_a.clone(), expr_b.clone()), NOR, 0), expr_b);
assert_eq!(beta(app(expr_b.clone(), expr_a.clone()), NOR, 0), expr_a);

[julianzxue]

That did the trick. It's so obvious but escaped me as the solution. Thanks again!

…

On Sat, Feb 11, 2023 at 8:52 AM ljedrz ***@***.***> wrote: Disclaimer: I haven't played with lambda calculus for a good while now, so please take this with a grain of salt 😃. I think it's just the fact that you need to add some extra explicit parentheses, otherwise the parser will automatically fold/collapse some of the sub-expressions (as suggested by the results of your parsing); the following seems to do the trick: let expr_a = parse(r#"\a. (a (\b. (\c. (c (\d. (\e. (e d)))))))"#, Classic).unwrap(); let expr_b = parse(r#"\a. (a (\b. (\c. (c b))))"#, Classic).unwrap(); assert_eq!(beta(app(expr_a.clone(), expr_b.clone()), NOR, 0), expr_b); assert_eq!(beta(app(expr_b.clone(), expr_a.clone()), NOR, 0), expr_a); — Reply to this email directly, view it on GitHub <#47 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABCQGQPOYCWQJBQANBT6BLLWW6KRZANCNFSM6AAAAAAUUXJDKI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[ljedrz]

Glad to hear it; I'll close the issue then 👍.