title: Wanted: example(s) of PEG Grammar for deeply nested Python boolean expressions
body: <p>I would like an example of a PEG grammar for deeply nested Python boolean expressions. The PEG grammar can't be "very recursive" or this will lead to stack overflow. Support for '|', '&amp;', '(' and ')' required.</p>
  
  <p>Example of input: (a=1|b=1|c=1|d=1&amp;e=2)&amp;(f=2&amp;g=2&amp;h=2|i=3|j=3|k=3)</p>