account_invoice.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>
        <record id="view_account_invoice_streamline_analytic" model="ir.ui.view">
            <field name="name">view.account.invoice.streamline.analytic</field>
            <field name="model">account.invoice</field>
            <field name="inherit_id" ref="account.invoice_supplier_form" />
            <field name="arch" type="xml">

                <xpath
                    expr="//notebook/page/field[@name='invoice_line']/tree/field[@name='price_subtotal']"
                    position="after">
                    <field name="a1_id" />
                    <field name="a2_id" />
                    <field name="a3_id" />
                    <field name="a4_id" />
                    <field name="a5_id" />
                </xpath>

                <!-- Make the due date read-only when a payment term is selected. -->

                <xpath expr="//field[@name='date_due']" position="attributes">
                    <attribute name="attrs"><![CDATA[
                    {'readonly': [('payment_term', '!=', False)]}
                    ]]></attribute>
                </xpath>

            </field>
        </record>
    </data>
</openerp>