🚀 go-pugleaf

In article <698@btnix.UUCP> psanders@btnix.UUCP (Chameleon) writes:
>>If we assume that the following definitions are valid:
>
>1. Functional and logic language programs consist of assertions, and the 
>computation proceeds by a process of deduction from these assertions.

In a functional language, programs are built from a set of data
objects, some of which just happen to be functions, and can therefore
be applied to other objects...

>1. In Functional programming the assertions consist of equations

A function is a partial mapping from data objects to data objects. I view
the "equational" feature of functional languages as simply specifying
the domain of a function. An important point is that, since functions only
have to map from a domain (i.e. they aren't relations), you get higher-order
functions naturally (once you've decided on the semantics for environments
and closures) - you don't have to worry about the relational aspect.

>3. For functional programming the subject of discourse is functions and for 
>logic programming it is relations

As I said above - functional languages (I admit, I'm thinking of ML here...)
provide a variety of data objects, some of which happen to be functions.
Admittedly, interesting things can't happen unless you use functions...

>then is functional programming a subclass of logic programming ?

I think they have some things in common, but not very much, since there are
serious theoretical points concerning the features which make sense in
either domain (e.g. higher-order functions, negation, equality, decidability,
unification, backtracking, termination, ...).

>Paul Sanders.
>E-mail (UUCP)	PSanders@axion.bt.co.uk (...!ukc!btnix!psanders)
>Organisation	British Telecom Research Laboratories, Ipswich UK.


-- 
Nick Rothwell,	Laboratory for Foundations of Computer Science, Edinburgh.
		nick%lfcs.ed.ac.uk@nss.cs.ucl.ac.uk
		<Atlantic Ocean>!mcvax!ukc!lfcs!nick
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...while the builders of the cages sleep with bullets, bars and stone,
they do not see your road to freedom that you build with flesh and bone.