haskell - let 表达式中元组的类型检查算法

Question

这个块给

f = let (x1, x2, x3) = (\y1 -> (y1, y1), \y2 -> x1 (x1 y2), \y3 -> x2 (x2 y3))
    in x1

错误：

Occurs check: cannot construct the infinite type: t1 ~ (t1, t1)
Relevant bindings include
  y2 :: t1 (bound at test.hs:1:43)
  x1 :: t1 -> (t1, t1) (bound at test.hs:1:10)
  x2 :: t1 -> (t1, t1) (bound at test.hs:1:14)
  x3 :: t1 -> (t1, t1) (bound at test.hs:1:18)
In the first argument of ‘x1’, namely ‘(x1 y2)’
In the expression: x1 (x1 y2)

我想知道let表达式中元组类型检查背后的算法。当左侧有一个变量时，我知道 Hindley-Milney 类型检查算法。我想知道在元组/列表等情况下是否有任何特殊算法。