Continua that are approximative absolute neighborhood retracts (AANR’s) are characterized as absolute terminal retracts, i.e., retracts of continua in which they are embedded as terminal subcontinua. This implies that any AANR continuum has a dense arc component, and that any ANR continuum is an absolute terminal retract. It is proved that each absolute retract for any of the classes of: tree-like continua, $\lambda $-dendroids, dendroids, arc-like continua and arc-like $\lambda $-dendroids is an approximative absolute retract (so it is an AANR). Consequently, all these continua have the fixed point property, which is a new result for absolute retracts for tree-like continua. Related questions are asked.
This study deals with a short but little researched episode in the life of Henry of Isernia, an Italian master of ars dictaminis, who came to the court of King Ottokar II of Bohemia in the early 1270s. Henry’s letter collection contains nine letters relating to his temporary stay at the Premonstratensian monastery in Strahov. These letters are impressive, but hardly interpretable, historical sources, and are also the only ones describing the circumstances of the election of a new Abbot of Strahov that probably took place in 1274. The reliability and credibility of Henry’s sometimes exaggerated and emotionally charged narratives were assessed by comparing their historical and biographical content with existing documents and memorial sources, such as monastery necrologies and annals.
Abbasid Revolution was one of the most important events of medieval Islamic history. The Umayyad autocratic rule privileged Syrian Arab tribes and ignored ambitions of new converts to Islam. The initiative to the fall of Umayyad dynasty came from Shiite opposition organized by Hashimiya sect. The revolt of both Arabs and Iranian converts was led by Abu Muslim, who in 747 raised black flags of Abbasid dynasty in Khorasan. However, after the victory Abu Muslim himself was executed by his masters and Abbasid despotic rule was imposed on the Arab-Muslim Empire.