0
$\begingroup$

I learned that expressions are left associative while abstraction are right associative, however, while solving some examples i faced this problem. Succ 3 Succ 2 when i applied left associativety i got (Succ 3) Succ) 2 which was extremely long to solve. However, i saw this guy on the internet, he said that we should parse it as Succ (3 Succ 2) which is Succ ( Succ Succ Succ 2) and the result is 6. AND THE ANSWER IS RIGHT! So now i am confused, during execution, should use the left or the right rule??

Improve this question
$\endgroup$
3
  • 1
    $\begingroup$ Application is left-associative (see e.g. en.wikipedia.org/wiki/…). Succ ( Succ Succ Succ 2) expansion can't possibly be correct since it doesn't follow any associativity rule, be it left or right. I also don't understand why ((Succ 3) Succ) 2 is extremely long to solve. 6 is indeed the correct answer. $\endgroup$
    – user114966
    Mar 12, 2021 at 0:55
  • $\begingroup$ so maybe it's not "extremely" long , but it's essential that i know the definition to solve it, unfortunately our test doesn't include a cheat sheet , so i don't think it's meant to be solved the conventional way. Do you know of any fast way i can solve this without using the definitions ? lambdacalc.io this solver solved it in 49 steps which is unreasonably long for an MCQ question , that's why i said it was long $\endgroup$
    – user28324
    Mar 12, 2021 at 8:17
  • $\begingroup$ This can be solved in 2 steps, by definition of Succ and definition of what you get after simplifying Succ 3. $\endgroup$
    – user114966
    Mar 12, 2021 at 13:43

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.