//@version=6
strategy("LANTERN price approximation", overlay = true,
  initial_capital = 10000, pyramiding = 0,
  default_qty_type = strategy.fixed,
  default_qty_value = 1,
  commission_type = strategy.commission.cash_per_order,
  commission_value = 1, slippage = 1,
  margin_long = 100, margin_short = 100)
if not timeframe.isdaily
    runtime.error("Use daily bars")
ceiling = ta.highest(close, 3)[1]
signal = not na(ceiling) and close > ceiling
justExited = ta.change(strategy.closedtrades) > 0
if barstate.isconfirmed
    if signal and strategy.position_size == 0 and
      not justExited
        strategy.entry("L", strategy.long, qty = 10)
    if strategy.position_size > 0
        entryBar = strategy.opentrades.entry_bar_index(0)
        if bar_index - entryBar >= 2
            strategy.close("L")
plot(ceiling, "Prior three-close maximum", color.gray)