Only use get_dual method for Or/And
Only use get_dual method for Or/And

GtTmy/pyeda,GtTmy/pyeda,GtTmy/pyeda,sschnug/pyeda,pombredanne/pyeda,sschnug/pyeda,cjdrake/pyeda,karissa/pyeda,karissa/pyeda,pombredanne/pyeda,cjdrake/pyeda,cjdrake/pyeda,sschnug/pyeda,karissa/pyeda,pombredanne/pyeda