Re: Inverse function (and ray tracing)

2000-01-03 Thread Brett_A . _Letner
>> I understood (apparently correctly) that Brett *knows* the inverse of >> functions he is interested in. Exactly. >> The problem is that in Haskell it is not possible to distinguish >> between functions, they do not belong to the Eq class Yes, I believe this is the heart of the problem. A

Re: Inverse function (and ray tracing)

2000-01-03 Thread Jerzy Karczmarczuk
Brett A. Letner precises his wishes concerning the inverse function. Somebody objected : > >> that is not possible in the general case. > >> Not to forget that even if it was, not all functions has inverses. I understood (apparently correctly) that Brett *knows* the inverse

inverse function

1999-12-30 Thread S.D.Mechveliani
[EMAIL PROTECTED] writes >> Do you want to have a function >> inverse :: (a -> b) -> (b -> a) >> so that (inverse f) . f = id >> ? >> [] >> that is not possible in the general case. >> Not to forget that even if it was, not all functions has inverses. > Perhaps I should elaborate. The specif

Re: Inverse function

1999-12-30 Thread Brett_A . _Letner
>> Do you want to have a function >> inverse :: (a -> b) -> (b -> a) >> so that (inverse f) . f = id >> ? Yes. >> that is not possible in the general case. >> Not to forget that even if it was, not all functions has inverses. I would like to do this for 3 specific cases, where I would supply th

Re: Inverse function

1999-12-30 Thread Martin Norbäck
Wed Dec 29 1999, [EMAIL PROTECTED] -> > Is it possible to define an inverse function such that given the functions > f,g, and h and their inverses f',g', and h', the inverse function would > return the appropriate inverse? > e.g. > inverse(f)=f' > inve

inverse function. Reply

1999-12-29 Thread S.D.Mechveliani
[EMAIL PROTECTED] writes > Is it possible to define an inverse function such that given the functions > f,g, and h and their inverses f',g', and h', the inverse function would > return the appropriate inverse? > e.g. > inverse(f)=f' > inverse(g)=g'

Inverse function

1999-12-29 Thread Brett_A . _Letner
Haskell group- Is it possible to define an inverse function such that given the functions f,g, and h and their inverses f',g', and h', the inverse function would return the appropriate inverse? e.g. inverse(f)=f' inverse(g)=g' inverse(h)=h' I'm a newbie to