testfile.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <form>
        <xpath expr="//">
            <!-- readonly should give: -->
            <!-- (field1 == 'yes' and field2 == 'yes') or (field3 == 'yes' or field4 == 'yes') or field5 == 'yes' and field6 == 'yes' -->
            <field attrs="{'invisible': True, 'readonly': ['|', '|', '&amp;', ('field1', '=', 'yes'), ('field2', '=', 'yes'), '|', ('field3', '=', 'yes'), ('field4', '=', 'yes'), ('field5', '=', 'yes'), ('field6', '=', 'yes')], 'required': [('field', 'in', ['a', 'b', 'c'])], 'column_invisible': 0}" name="name"/>
        </xpath>
        <xpath expr="//." position="attributes">
            <attribute name="attrs">{'invisible': True, 'readonly': [('otherfield', '=', 'yes')], 'required': [('field', 'in', ['a', 'b', 'c'])], 'column_invisible': 0}</attribute>
        </xpath>
        <xpath expr="//test_states_simple_case">
            <field states="draft,done"/>
        </xpath>
        <xpath expr="//test_states_attrs_simple_case">
            <attribute name="states">draft</attribute>
        </xpath>
        <xpath expr="//test_states_with_invisible_existing">
            <field states="draft,done" attrs="{'invisible': [('testfield', '=', 'hello world')]}"/>
        </xpath>
        <xpath expr="//test_states_attrs_with_invisible_existing" position="attributes">
            <attribute name="attrs">{
            'invisible': [
                '|', 
                '|',
                '&amp;',
                ('test1', 'in', [1, 2, 3]),
                ('test2', 'in', [2, 3, 4]),
                ('test3', '=', 'hello'),
                ('test4', 'in', [%('testmodule.test_xml_id')d, %('testmodule.test_xml_id_2')d])
            ]
            }</attribute>
            <attribute name="states">draft,done</attribute>
        </xpath>
        <xpath expr="//test_states_attrs_with_invisible_existing_and_invisible_single_and">
            <attribute name="attrs">{'invisible': ['&amp;', ('test8', '=', True)]}</attribute>
            <attribute name="states">draft,done</attribute>
        </xpath>
        <field name="test" attrs="{
            'invisible': [
                '|', 
                '|',
                '&amp;',
                ('test1', 'in', [1, 2, 3]),
                ('test2', 'in', [2, 3, 4]),
                ('test3', '=', 'hello'),
                ('test4', 'in', [%('testmodule.test_xml_id')d, %(testmodule.test_xml_id_2)d])
            ]
        }"/>
        <!-- Case given by odoo, single '|' with states - can cause bug while should be accepted -->
        <button name="action_open_action_coupon_program" attrs="{'invisible': ['|', ('allow_modification', '=', False)]}" context="{'enable_add_temporary': 1}" class="btn btn-secondary" string="Actions" type="object" states="draft,sent,sale"/>
    </form>
</odoo>