From 037e86aeaf213bc72033801b84bcdc4bafd03c74 Mon Sep 17 00:00:00 2001
From: josd <josderoo@gmail.com>
Date: Sun, 2 Mar 2025 20:30:14 +0100
Subject: [PATCH] refreshing

---
 .../kaprekar-constant-query.n3                |  3 +-
 .../kaprekar-constant/kaprekar-constant.n3    | 37 -------------------
 .../kaprekar-constant/kaprekar-constant.pl    | 33 +++++++++++++++++
 reasoning/kaprekar-constant/test              |  2 +-
 4 files changed, 36 insertions(+), 39 deletions(-)
 delete mode 100644 reasoning/kaprekar-constant/kaprekar-constant.n3
 create mode 100644 reasoning/kaprekar-constant/kaprekar-constant.pl

diff --git a/reasoning/kaprekar-constant/kaprekar-constant-query.n3 b/reasoning/kaprekar-constant/kaprekar-constant-query.n3
index 0ac993309..fa20abf98 100644
--- a/reasoning/kaprekar-constant/kaprekar-constant-query.n3
+++ b/reasoning/kaprekar-constant/kaprekar-constant-query.n3
@@ -2,7 +2,8 @@
 @prefix : <https://eyereasoner.github.io/ns#>.
 
 {
-    10000 log:repeat ?I.
+    ("consult" "./kaprekar-constant.pl") log:program true.
+    ("between" 0 9999 ?I) log:program true.
     ?I :recursionCount ?N.
 } => {
     ?I :recursionCount ?N.
diff --git a/reasoning/kaprekar-constant/kaprekar-constant.n3 b/reasoning/kaprekar-constant/kaprekar-constant.n3
deleted file mode 100644
index 9024eabf7..000000000
--- a/reasoning/kaprekar-constant/kaprekar-constant.n3
+++ /dev/null
@@ -1,37 +0,0 @@
-@prefix math: <http://www.w3.org/2000/10/swap/math#>.
-@prefix list: <http://www.w3.org/2000/10/swap/list#>.
-@prefix log: <http://www.w3.org/2000/10/swap/log#>.
-@prefix : <https://eyereasoner.github.io/ns#>.
-
-# recursive case till 6174 is reached
-{ ?A :kaprekar (?B ?C) } <= {
-    ?A math:notEqualTo 0.
-    ?A :numberToDigits ?D.
-    (?D "=<") list:sort ?E.
-    (?D ">=") list:sort ?F.
-    ?E :digitsToNumber ?G.
-    ?F :digitsToNumber ?H.
-    (?H ?G) math:difference ?I.
-    (?B 1) math:sum ?J.
-    ({ ?I math:equalTo 6174 } { ?C log:equalTo ?J } { ?I :kaprekar (?J ?C) }) log:ifThenElseIn ?SCOPE.
-}.
-
-# convert 4 digit number to digits
-{ ?A :numberToDigits (?B ?C ?D ?E) } <= {
-    (?A 1000) math:integerQuotient ?B.
-    (?A 1000) math:remainder ?F.
-    (?F 100) math:integerQuotient ?C.
-    (?F 100) math:remainder ?G.
-    (?G 10) math:integerQuotient ?D.
-    (?G 10) math:remainder ?E.
-}.
-
-# convert 4 digits to number
-{ (?A ?B ?C ?D) :digitsToNumber ?E } <= {
-    ((?A 1000)!math:product (?B 100)!math:product (?C 10)!math:product ?D) math:sum ?E.
-}.
-
-# recursion count
-{ ?I :recursionCount ?J } <= {
-    ?I :kaprekar (0 ?J).
-}.
diff --git a/reasoning/kaprekar-constant/kaprekar-constant.pl b/reasoning/kaprekar-constant/kaprekar-constant.pl
new file mode 100644
index 000000000..d101ab719
--- /dev/null
+++ b/reasoning/kaprekar-constant/kaprekar-constant.pl
@@ -0,0 +1,33 @@
+% Kaprekar's constant
+
+% recursive case till 6174 is reached
+'<https://eyereasoner.github.io/ns#kaprekar-constant>'(A, B, C) :-
+    A =\= 0,
+    '<https://eyereasoner.github.io/ns#numberToDigits>'(A, D),
+    keysort(D, E),
+    reverse(E, F),
+    '<https://eyereasoner.github.io/ns#digitsToNumber>'(E, G),
+    '<https://eyereasoner.github.io/ns#digitsToNumber>'(F, H),
+    I is H-G,
+    J is B+1,
+    (   I =:= 6174
+    ->  C = J
+    ;   '<https://eyereasoner.github.io/ns#kaprekar-constant>'(I, J, C)
+    ).
+
+% convert 4 digit number to digits
+'<https://eyereasoner.github.io/ns#numberToDigits>'(A, [B-0, C-0, D-0, E-0]) :-
+    B is A // 1000,
+    F is A rem 1000,
+    C is F // 100,
+    G is F rem 100,
+    D is G // 10,
+    E is G rem 10.
+
+% convert 4 digits to number
+'<https://eyereasoner.github.io/ns#digitsToNumber>'([A-0, B-0, C-0, D-0], E) :-
+    E is A*1000+B*100+C*10+D.
+
+% recursion count
+'<https://eyereasoner.github.io/ns#recursionCount>'(I, J) :-
+    '<https://eyereasoner.github.io/ns#kaprekar-constant>'(I, 0, J).
diff --git a/reasoning/kaprekar-constant/test b/reasoning/kaprekar-constant/test
index c0bfe677e..f40e76e87 100755
--- a/reasoning/kaprekar-constant/test
+++ b/reasoning/kaprekar-constant/test
@@ -1,2 +1,2 @@
 #!/bin/bash
-eye --quiet --skolem-genid 8b98b360-9a70-4845-b52c-c675af60ad01 --wcache https://eyereasoner.github.io/eye/reasoning .. --nope https://eyereasoner.github.io/eye/reasoning/kaprekar-constant/kaprekar-constant.n3 --query https://eyereasoner.github.io/eye/reasoning/kaprekar-constant/kaprekar-constant-query.n3 --output kaprekar-constant-answer.n3
+eye --quiet --skolem-genid 8b98b360-9a70-4845-b52c-c675af60ad01 --wcache https://eyereasoner.github.io/eye/reasoning .. --nope --query https://eyereasoner.github.io/eye/reasoning/kaprekar-constant/kaprekar-constant-query.n3 --output kaprekar-constant-answer.n3