```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Labor-Antip-Antic@12:29:46</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>1</hlevel>
            <item_name>Laboratory Tests</item_name>
            <item_key>\\i2b2_LABS\i2b2\Labtests\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Labtests</tooltip>
            <class>ENC</class>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>2</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>3</hlevel>
            <item_name>Antiphospholipid Antibodies</item_name>
            <item_key>\\i2b2_LABS\i2b2\Labtests\LAB\(LLB6) Coagulation\(LLB7) Antiphospholipid Antibodies\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Labtests \ Coagulation \ Antiphospholipid Antibodies</tooltip>
            <class>ENC</class>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>3</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>4</hlevel>
            <item_name>Anticardiolipin IgG (Group:ACLIgG)</item_name>
            <item_key>\\i2b2_LABS\i2b2\Labtests\LAB\(LLB6) Coagulation\(LLB7) Antiphospholipid Antibodies\ACLIgG\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Labtests \ Coagulation \ Antiphospholipid Antibodies \ Anticardiolipin IgG (Group:ACLIgG)</tooltip>
            <class>ENC</class>
            <constrain_by_value>
                <value_operator>EQ</value_operator>
                <value_constraint>@</value_constraint>
                <value_type>FLAG</value_type>
            </constrain_by_value>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find all patients who have had any laboratory tests performed with Antiphospholipid Antibodies, specifically Anticardiolipin IgG (Group:ACLIg) with a value of "@" in the database, regardless of the timing of the test, and with a high level of specificity and accuracy.