<documentation title="Require Explicit Boolean Operator Precedence"
    >
    <standard>
    <![CDATA[
    Forbids mixing different binary boolean operators (&&, ||, and, or, xor) within a single expression without making precedence clear using parentheses.
    ]]>
    </standard>
    <code_comparison>
        <code title="Valid: Making precedence clear with parentheses.">
        <![CDATA[
$one = false;
$two = false;
$three = true;

$result = <em>($one && $two) || $three</em>;
$result2 = <em>$one && ($two || $three)</em>;
$result3 = <em>($one && !$two) xor $three</em>;
$result4 = <em>$one && (!$two xor $three)</em>;

if (
    <em>($result && !$result3)
    || (!$result && $result3)</em>
) {}
        ]]>
        </code>
        <code title="Invalid: Not using parentheses.">
        <![CDATA[
$one = false;
$two = false;
$three = true;

$result = <em>$one && $two || $three</em>;

$result3 = <em>$one && !$two xor $three</em>;


if (
    <em>$result && !$result3
    || !$result && $result3</em>
) {}
        ]]>
        </code>
    </code_comparison>
</documentation>