Functional Logic Programming (or FLP in short) is a composite paradigm unifiying the Functional Programming and Logic Programming paradigms.
Prominent examples of FLP languages are Curry, Mercury and others.
Questions tagged [functional-logic-progr]
10 questions
5
votes
1 answer
Haskell: Combining existential and universal quantifiers fails unexpectedly
I am trying to model the following logical implication in Haskell with GHC, version 8.6.5:
(∀ a. ¬ Φ(a)) → ¬ (∃ a: Φ(a))
The definitions I used are the following:
{-# LANGUAGE RankNTypes, GADTs #-}
import Data.Void
-- Existential quantification…
Nicolas Malebranche
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4
votes
2 answers
Compact vs full/verbose definition of the inverse combinator/operator in Curry
The rather fascinating 2013 introductory post to the Haskell based KiCS2 implementation of Curry by Wolfgang Jeltsch, A Taste of Curry, provides the following definition for the inverse combinator:
inverse :: (a -> b) -> (b -> a)
inverse f y | f x…
Erik Kaplun
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3
votes
1 answer
Need clarification in understanding a custom core.logic constraint
I was trying to understand a custom core.logic constraint as defined below,
(defne lefto
"x appears to the left of y in collection l."
[x y l]
([_ _ [x . tail]] (membero y tail))
([_ _ [_ . tail]] (lefto x y tail)))
How to interpret _ and .…
Kannan Ramamoorthy
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3
votes
3 answers
Discussion about Abductive logic programming vs Answer Set Programming
I am looking to clarify the some things about abductive logic programming vs. Answer set programming.
I with some classmates are creating a game. In this game there are "heroes" (special npcs). The heroes have goals and behaviors.
(All of this is…
ssmoot
- 31
- 2
1
vote
0 answers
Is it possible to insert a Clojure statement in the middle of a series of core.logic calls, "à la Prolog"?
Prolog mixes logic (fallible) goals, and (infallible) processes like write/2 or assert/1. Is it possible to do so with Clojure's core.logic?
For example:
(pldb/with-db myFacts
(l/run* [x y]
(person x)
(println "we found a…
Hugolin Bergier
- 87
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1
vote
1 answer
If & Else & Pattern Matching in SML altogether?
I've been trying to compile this piece of code for 3 hours and nothing improved.
I know that my datatype compiles without problem and also the first case of pattern matching . But when the second case comes in (a node with two nodes for children )…
tonythestark
- 519
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1
vote
2 answers
Inverting `member` in Curry (PAKCS) gives no answers
With this definition:
member _ [] = False
member x (h:t) = if x == h then True else member x t
PAKCS 2.0.1 (from Ubuntu 18.04) gives no answers, warnings or errors:
Top-level binding with no type signature:
member :: Prelude.Eq a => a ->…
MWB
- 11,740
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0
votes
1 answer
Find number of successes from a list of terms/goals
I have written the following predicate exactly/2 that succeeds if exactly N of the numbers in the list L are equal to 1:
:- pred exactly(int, list(int)).
:- mode exactly(in, in) is semidet.
:- mode exactly(out, in) is det.
exactly(N, L) :-
…
Zehanort
- 458
- 2
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0
votes
2 answers
How can I design a 2-1 multiplexer with enable using only NAND gates?
So, I manage to design something but I need confirmation and my real question is the following:
How can I design 4-1 multiplexer using 2 multiplexers designed as in the title of the question (using only NANDs) plus as many NOR gates as I need?
To…
hack-is-art
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0
votes
1 answer
Generating a parser with `inverse`, with constraints on the grammar
I recently followed through A Taste of Curry, and afterwards decided to put the trivial arithmetic parser example to test, by writing a somewhat more substantial parser: a primitive but correct and functional HTML parser.
I ended up with a working…
Erik Kaplun
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