headAt : xs i ->
  with (
    tmp : slice xs i (i + 1);
  ) ->
    tmp.0;

get2 : grid r c ->
  headAt (headAt grid r) c;

safeGet2 : grid r c ->
  with (
    rows : length grid;
    cols : length (headAt grid 0);
    rOk : r >= 0 and r < rows;
    cOk : c >= 0 and c < cols;
  ) ->
    when rOk and cOk is
      true then get2 grid r c
      _    then 0;

range : lo hi ->
  when lo >= hi is
    true then []
    _    then prepend lo (range (lo + 1) hi);

sum : xs ->
  reduce (acc x -> acc + x) 0 xs;

deltas : [-1, 0, 1];

neighborsValues : grid r c ->
  reduce (acc dr -> reduce (acc2 dc ->   when dr = 0 and dc = 0 is
    true then acc2
    _    then append acc2 (safeGet2 grid (r + dr) (c + dc))) acc deltas) [] deltas;

countNeighbors : grid r c ->
  sum (neighborsValues grid r c);

nextCell : grid r c ->
  with (
    cell : get2 grid r c;
    n : countNeighbors grid r c;
    isAlive : cell = 1;
    born : cell = 0 and n = 3;
    survive : isAlive and n = 2 or n = 3;
  ) ->
    when survive is
      true then 1
      _    then 
        when born is
          true then 1
          _    then 0;

rowNext : grid w r ->
  map (c -> nextCell grid r c) (range 0 w);

step : grid ->
  with (
    h : length grid;
    w : length (headAt grid 0);
  ) ->
    map (r -> rowNext grid w r) (range 0 h);

g0 : [
  [0, 1, 0, 0, 0],
  [0, 0, 1, 0, 0],
  [1, 1, 1, 0, 0],
  [0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0]
];
g1 : step g0;
g2 : step g1;
g3 : step g2;
g4 : step g3;
blinker0 : [[1, 1, 1], [0, 0, 0], [0, 0, 0]];
blinker1 : step blinker0;
blinker2 : step blinker1;
toad0 : [
  [0, 1, 1, 1],
  [1, 1, 1, 0],
  [0, 0, 0, 0],
  [0, 0, 0, 0]
];
toad1 : step toad0;
toad2 : step toad1;
beacon0 : [
  [1, 1, 0, 0],
  [1, 1, 0, 0],
  [0, 0, 1, 1],
  [0, 0, 1, 1]
];
beacon1 : step beacon0;
beacon2 : step beacon1;
block : [[1, 1], [1, 1]];
block1 : step block;
beehive : [[0, 1, 1, 0], [1, 0, 0, 1], [0, 1, 1, 0]];
beehive1 : step beehive;
pulsar0 : [
  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  [0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1],
  [0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0],
  [0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1],
  [0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0],
  [0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1],
  [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0],
  [0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0]
];
pulsar1 : step pulsar0;
pulsar2 : step pulsar1;
pulsar3 : step pulsar2;

// Enhanced Conway's Game of Life display using io.print
io.print "";
io.print "Conway's Game of Life - Pattern Evolution";
io.print "==========================================";

io.print "";
io.print "Glider Pattern Evolution:";
io.print "Step 0:";
io.print g0;
io.print "Step 1:";
io.print g1;
io.print "Step 2:";
io.print g2;
io.print "Step 3:";
io.print g3;
io.print "Step 4:";
io.print g4;

io.print "";
io.print "Blinker Oscillation:";
io.print "Step 0:";
io.print blinker0;
io.print "Step 1:";
io.print blinker1;
io.print "Step 2:";
io.print blinker2;

io.print "";
io.print "Toad Breathing Pattern:";
io.print "Step 0:";
io.print toad0;
io.print "Step 1:";
io.print toad1;
io.print "Step 2:";
io.print toad2;

io.print "";
io.print "Beacon Blinking:";
io.print "Step 0:";
io.print beacon0;
io.print "Step 1:";
io.print beacon1;
io.print "Step 2:";
io.print beacon2;

io.print "";
io.print "Still Life Patterns:";
io.print "Block:";
io.print block;
io.print "Beehive:";
io.print beehive;

io.print "";
io.print "Pulsar Oscillation (Period 3):";
io.print "Step 0:";
io.print pulsar0;
io.print "Step 1:";
io.print pulsar1;
io.print "Step 2:";
io.print pulsar2;
io.print "Step 3:";
io.print pulsar3;

// End of program - visual patterns shown above