diff --git a/pl/09.2.pl b/pl/09.2.pl
index 0c5a15d..5db075a 100644
--- a/pl/09.2.pl
+++ b/pl/09.2.pl
@@ -28,91 +28,42 @@ basins(A, [P|Ps], [B|Bs]) :-
     length(Bas, B),
     basins(A, Ps, Bs).
 
-low_point([[A,B|_]|[[C|_]|_]], 0, 0) :-
-    A < B, A < C.
+fetch_value(A, [X, Y], V) :-
+    nth0(Y, A, R),
+    nth0(X, R, V).
 
-low_point([A|As], X, 0) :-
-    X > 0,
-    nth0(X, A, R0),
-    X0 is X - 1,
-    X1 is X + 1,
-    nth0(X0, A, R1),
-    R0 < R1,
-    (
-        (length(A, X1), length([A|As], 1));
-        (length([A|As], 1), nth0(X1, A, R2), R0 < R2);
-        (length(A, X1), nth0(1, [A|As], E), nth0(X, E, E0), R0 < E0);
-        (nth0(X1, A, R2), R0 < R2, nth0(1, [A|As], E), nth0(X, E, E0), R0 < E0)
-    ).
-
-low_point(A, 0, Y) :-
-    Y > 0,
-    nth0(Y, A, [R0,R1|_]),
-    R0 < R1,
-    Y0 is Y - 1,
-    Y1 is Y + 1,
-    nth0(Y0, A, [T0|_]),
-    R0 < T0,
-    (
-        length(A, Y1);
-        (nth0(Y1, A, [E0|_]), R0 < E0)
-    ).
+fetch_values(_, [], []).
+fetch_values(A, [P|Ps], [V|Vs]) :-
+    fetch_value(A, P, V),
+    fetch_values(A, Ps, Vs).
 
 low_point(A, X, Y) :-
-    Y > 0,
-    X > 0,
-    nth0(Y, A, R),
-    nth0(X, R, R0),
-    X0 is X - 1,
-    Y0 is Y - 1,
-    X1 is X + 1,
-    Y1 is Y + 1,
-    nth0(X0, R, R1),
-    R0 < R1,
-    nth0(Y0, A, E),
-    nth0(X, E, E0),
-    R0 < E0,
+    valid_paths(A, X, Y, P),
+    fetch_values(A, P, V),
+    fetch_value(A, [X, Y], V0),
+    min_list(V, V1),
+    V1 > V0.
+
+low_points_rest([A|As], X, Y, Rs) :-
+    length(A, W),
     (
-        (length(A, Y1), length(R, X1));
-        (length(A, Y1), nth0(X1, R, R2), R0 < R2);
-        (length(R, X1), nth0(Y1, A, T), nth0(X, T, T0), R0 < T0);
-        (nth0(X1, R, R2), R0 < R2, nth0(Y1, A, T), nth0(X, T, T0), R0 < T0)
+        (X > 0, X0 is X - 1, low_points([A|As], X0, Y, Rs));
+        (X = 0, Y > 0, X0 is W - 1, Y0 is Y - 1, low_points([A|As], X0, Y0, Rs))
     ).
 
-low_points([A|As], Ret) :-
-    length([A|As], Y),
-    length(A, X),
-    X0 is X - 1,
-    Y0 is Y - 1,
-    low_points([A|As], X0, Y0, Ret).
-low_points(A, 0, 0, [[0, 0]]) :-
-    low_point(A, 0, 0).
-low_points(A, 0, 0, []) :-
-    \+ low_point(A, 0, 0).
+low_points(A, 0, 0, [[0, 0]]) :- low_point(A, 0, 0).
+low_points(A, 0, 0, []) :- \+ low_point(A, 0, 0).
 low_points(A, X, Y, [[X, Y]|Rs]) :-
-    X > 0,
     low_point(A, X, Y),
-    X0 is X - 1,
-    low_points(A, X0, Y, Rs).
+    low_points_rest(A, X, Y, Rs).
 low_points(A, X, Y, Rs) :-
-    X > 0,
-    \+ low_point(A, X, Y),
-    X0 is X - 1,
-    low_points(A, X0, Y, Rs).
-low_points([A|As], 0, Y, [[0, Y]|Rs]) :-
-    Y > 0,
-    length(A, Len),
-    low_point([A|As], 0, Y),
-    Y0 is Y - 1,
-    X0 is Len - 1,
-    low_points([A|As], X0, Y0, Rs).
-low_points([A|As], 0, Y, Rs) :-
-    Y > 0,
-    length(A, Len),
-    \+ low_point([A|As], 0, Y),
-    Y0 is Y - 1,
-    X0 is Len - 1,
-    low_points([A|As], X0, Y0, Rs).
+    low_points_rest(A, X, Y, Rs).
+low_points([A|As], Ret) :-
+    length([A|As], H),
+    length(A, W),
+    X0 is W - 1,
+    Y0 is H - 1,
+    low_points([A|As], X0, Y0, Ret).
 
 high_neighbor(A, [X1, Y1], [X0, Y0]) :-
     nth0(Y1, A, R1),