notation_error_pos.lean:6:7: error: failed to synthesize type class instance for
⊢ has_one string
notation_error_pos.lean:8:7: error: failed to synthesize type class instance for
⊢ has_one string
notation_error_pos.lean:10:7: error: failed to synthesize type class instance for
⊢ has_one string
notation_error_pos.lean:12:7: error: failed to synthesize type class instance for
x : string
⊢ has_add string