matchErrorLocation.lean:5:10: error: type mismatch
  h he
has type
  False
but it is expected to have type
  α
failed to synthesize instance
  CoeT False _ α
with resulting expansion
  match xs ,  Eq.refl  _  ,   (  x  :  _  )  → xs  =  x  →  _ with
  | []   , he=> h he
  | x::_ , he=> x 
while expanding
  match he:xs with
  | []   => h he
  | x::_ => x