MultiDataTrigger : Handle OR condition

Building on my previous post on MultiDataTrigger, we saw that MultiDataTrigger generally works for AND conditions (all conditions should be true to fire the trigger to update the property)

What would you do to handle OR condition?

<Style x:Key="pricestyle" TargetType="TextBox">
            <Setter Property="Visibility" Value="Collapsed"/>
            <Style.Triggers>
                <MultiDataTrigger>
                    <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding AllowCheck}" Value="True"/>
                    </MultiDataTrigger.Conditions>
                        <Setter Property="Visibility" Value="Visible"/>
                </MultiDataTrigger>
                <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                        <Condition Binding="{Binding Action}" Value="SELL"/>
                    </MultiDataTrigger.Conditions>
                        <Setter Property="Visibility" Value="Visible"/>
                </MultiDataTrigger>
            </Style.Triggers>
        </Style>

Effectively you would need to write 2 multi data triggers to get this working.

Side notes (not related to this post topic)
http://stackoverflow.com/questions/17598200/datatrigger-binding-in-wpf-style
http://stackoverflow.com/questions/15814639/consolidating-common-wpf-styles