完整名稱：Std.Arithmetic.ApplyIfEqualL
operation ApplyIfEqualL<'T>(action : ('T => Unit is Adj + Ctl), c : BigInt, xs : Qubit[], target : 'T) : Unit is Adj + Ctl
總結
計算 if (c == x) { action(target) }，也就是說，如果 BigInt 值 action 等於小端量子位緩存器 target，c 就會套用至 x