I urgently need help with my wxmaxima percolation algorithm, I have no idea what's wrong with it and I need someone to take a look at it and help me.

[michu999]

`percolation(matrix, labels) :=
block(
label: 0,
label_of: makelist(makelist(0, j, 1, length(matrix[1])), i, 1, length(matrix)),
connected: lambda([label1, label2], label1 = label2),
find_root: lambda([label], if labels[label] = label then label else find_root(labels[label])),
union: lambda([label1, label2], labels[find_root(label1)]: find_root(label2)),
for i thru length(matrix) do
for j thru length(matrix[i]) do
if matrix[i][j] = 1 then
if i = 1 and j = 1 then (
label: label + 1,
push(label, labels)
) else if i = 1 then
if matrix[i][j-1] = 1 then
label_of[i][j]:= label_of[i][j-1]
else (
label: label + 1,
push(label, labels),
label_of[i][j]:= label
)
else if j = 1 then
if matrix[i-1][j] = 1 then
label_of[i][j]:= label_of[i-1][j]
else (
label: label + 1,
push(label, labels),
label_of[i][j]:= label
)
else if matrix[i][j-1] = 1 and matrix[i-1][j] = 1 then (
label_of[i][j]:= min(label_of[i][j-1], label_of[i-1][j]),
union(label_of[i][j-1], label_of[i-1][j])
) else if matrix[i][j-1] = 1 then
label_of[i][j]:= label_of[i][j-1]
else if matrix[i-1][j] = 1 then
label_of[i][j]:= label_of[i-1][j]
else (
label: label + 1,
push(label, labels),
label_of[i][j]:= label
),
for i thru length(labels) do
labels[i]:= find_root(labels[i]),
num_components: length(uniq(labels)),
if num_components > 1 then (
print("Perkolacja występuje"),
print("Liczba składowych: ", num_components)
) else
print("Perkolacja nie występuje")
);

matrix: [[8, 7, 9, 10, 11],
[10, 5, 9, 3, 3],
[7, 6, 4, 7, 2],
[11, 9, 7, 9, 8]];

labels: [];

percolation(matrix, labels);`

[michu999]

The error that appears whenever i try to launch the code:
[[8,7,9,10,11],[10,5,9,3,3],[7,6,4,7,2],[11,9,7,9,8]] assignment: attempting to assign read-only variable labels the value [] -- an error. To debug this try: debugmode(true);

[franzgraf]

labels is a reserved name, see https://maxima.sourceforge.io/docs/manual/maxima_8.html#index-labels-1