bad_error1.lean:4:22: error: unexpected argument at application
  nat.bit1_ne_bit0 n
given argument
  n
expected argument
  m
bad_error1.lean:4:22: error: unexpected argument at application
  nat.bit1_ne_bit0 sorry m
given argument
  m
expected argument
  n
bad_error1.lean:4:13: error: type mismatch at application
  ne.symm (nat.bit1_ne_bit0 sorry sorry)
term
  nat.bit1_ne_bit0 sorry sorry
has type
  bit1 sorry ≠ bit0 sorry
but is expected to have type
  bit1 m ≠ bit0 n