 Complete the following phrase:  According to the Jamestown Foundation, the TAK has been a rival to the PKK since 2006. From then on, the groups operations have been repeatedly at odds with Murat Karayılans and other PKK leaders repeated calls for a ceasefire followed by negotiations. However, Vera Eccarius-Kelly, a scholar of political science, has noted that there are no clear signs that indicate a struggle between the two groups. According to her, whilst TAK repeatedly damaged the PKKs efforts to negotiate cease-fires with unapproved bombings, in a way that has been compared to the Real IRA in the 