(FYI, there is a copy of the above-mentioned paper that doesn't require an ACM account available at http://www.cs.berkeley.edu/~jcondit/pl-prelim/hudak89functional.pdf.)
Hudak is just defining a series of higher-order infix operators and functions. (You have made some notational errors in the above-mentioned notation, so I am revising it to match the paper as below.) A backslash denotes a lambda symbol; i.e., whatever
Sorry about that.
3? ?f;g =\s -> g(fs)
I couldn't find this equation on p. 406 of the volume; where did you find it?
Again my transcription error.
In other words, the function "if'" applied to functions p and c is such that lambda p c -> (if (p s) then (c s) else s).
Hope this helps....
Thanks! It does. I think what threw me was that while there is enough redundancy in what he states for someone more clever than me, he would have explicitly stated before hand that he was defining the operators [:=], [+'], ['if] etc.:) thanks again.