[1, 2]
6
parserPrio.lean:28:7-28:10: error: ambiguous, possible interpretations 
  HMul.hMul (α := ?m) (β := ?m) (γ := ?m) 2 1
  
  List.cons (α := ?m) 1 (List.nil (α := ?m) : List ?m)
[1, 2, 3]