Parse error in where clausel when using operations on a term

[Querela]

See this example snippet:

>>> format_sql.format_sql('''select a.a from aaa a where ((a.b+1) = 2);''')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/koerner/miniconda3/envs/tests-sql/lib/python3.6/site-packages/format_sql/shortcuts.py", line 20, in format_sql
    parsed = list(parse(tokens))
  File "/home/koerner/miniconda3/envs/tests-sql/lib/python3.6/site-packages/format_sql/parser.py", line 762, in parse
    for statement, unused_count in _parse(toks):
  File "/home/koerner/miniconda3/envs/tests-sql/lib/python3.6/site-packages/format_sql/parser.py", line 756, in _parse
    statement, count = func(toks)
  File "/home/koerner/miniconda3/envs/tests-sql/lib/python3.6/site-packages/format_sql/parser.py", line 596, in _parse_where
    conditions, j = _parse_conditions(toks[1:])
  File "/home/koerner/miniconda3/envs/tests-sql/lib/python3.6/site-packages/format_sql/parser.py", line 701, in _parse_conditions
    raise InvalidCondition()
format_sql.parser.InvalidCondition

It seems that all (most?) queries with the following conditions <table>.<column> + 1 = <some other value> fail to parse:

select a.a from aaa a where a.b+1 = 2;