```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>(t) Medications-Medications@14:52:51</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <subquery_constraint>
        <first_query>
            <query_id>Event 1</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </first_query>
        <operator>LESS</operator>
        <second_query>
            <query_id>Event 2</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </second_query>
    </subquery_constraint>
    <subquery>
        <query_id>Event 1</query_id>
        <query_type>EVENT</query_type>
        <query_name>Event 1</query_name>
        <query_timing>SAMEINSTANCENUM</query_timing>
        <specificity_scale>0</specificity_scale>
        <panel>
            <panel_number>1</panel_number>
            <panel_timing>SAMEINSTANCENUM</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>Medications</item_name>
                <item_key>\\i2b2_MEDS\i2b2\Medications\</item_key>
                <item_icon>FA</item_icon>
                <tooltip>Medications</tooltip>
                <class>ENC</class>
                <constrain_by_modifier>
                    <modifier_name>Patient Instructions</modifier_name>
                    <modifier_key>\\i2b2_MEDS\Medication\Instructions\</modifier_key>
                    <applied_path>\i2b2\Medications\%</applied_path>
                </constrain_by_modifier>
                <item_is_synonym>false</item_is_synonym>
            </item>
        </panel>
    </subquery>
    <subquery>
        <query_id>Event 2</query_id>
        <query_type>EVENT</query_type>
        <query_name>Event 2</query_name>
        <query_timing>SAMEINSTANCENUM</query_timing>
        <specificity_scale>0</specificity_scale>
        <panel>
            <panel_number>1</panel_number>
            <panel_timing>SAMEINSTANCENUM</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>Medications</item_name>
                <item_key>\\i2b2_MEDS\i2b2\Medications\</item_key>
                <item_icon>FA</item_icon>
                <tooltip>Medications</tooltip>
                <class>ENC</class>
                <constrain_by_modifier>
                    <modifier_name>Route</modifier_name>
                    <modifier_key>\\i2b2_MEDS\Medication\Route\</modifier_key>
                    <applied_path>\i2b2\Medications\%</applied_path>
                </constrain_by_modifier>
                <item_is_synonym>false</item_is_synonym>
            </item>
        </panel>
    </subquery>
</ns4:query_definition>

```

I want to find medication events with their start dates within the same instance number, where the first event has no specificity scale and is constrained by the 'Patient Instructions' modifier, and the second event has the same timing, specificity scale, and is constrained by the 'Route' modifier. The query will compare the start dates of the two events and return results where the start date of the first event is less than the start date of the second event.