Inter-universal Teichmuller Theory I ------------------------------------ ・Corrected a misprint ("prime strip" ---> "prime-strip", 1 instance) in  Definition 4.1, (iv) ・Replaced the "$\ast$'s" by "$\divideontimes$'s" in Figs. I1.3, 4.4, and  made corresponding adjustments to the surrounding text ・Corrected a minor misprint ("Z^\hat" ---> "Z^\hat \otimes Q") in Example  5.1, (v) Inter-universal Teichmuller Theory II ------------------------------------- ・Corrected misprints ("structures structures") in Figs. I.3, 1.3 ・Corrected misprints (i.e., missing superscript "N's") in the  theta monoids (4 instances) and Gaussian monoids (1 instance)  that appear in the discussion of the Introduction ・Corrected a misprint concerning the hyperbolic curve introduced at  the beginning of \S 1 ・Corrected a misprint (i.e., "))" ---> ")") towards the end of Remark  1.5.2 ・Corrected a misprint (i.e., "))" ---> ")") in the first display of  Corollary 3.5, (ii) ・Corrected misprints concerning the \Theta-link in Remark 4.10.3, (i)  (1 instance), (ii) (3 instances), (iii) (1 instance) ・Corrected a misprint (a missing superscript "bad") in Remark 4.7.3, (i) ・Added a supplementary explanatory phrase to the sentence following the  display of Remark 1.8.1 ・Corrected a misprint (i.e., "\Psi" ---> "\Xi", 4 instances) in the final  sentence of Example 1.9, (i) ・Corrected a misprint (i.e., "(R,C,\Psi_R)" ---> "(R,C,\Phi)", 2 instances)  in Example 1.9, (ii) ・Corrected misprints (i.e., "\Psi" ---> "\Phi", 2 instances;  "(R,C,\Psi_R)" ---> "(R,C,\Phi)", 2 instances) in Example 1.9, (iii) ・Corrected a misprint (i.e., "(R,C,\Psi_R)" ---> "(R,C,\Phi)", 1 instance)  in Example 1.9, (iv) ・Slightly modified (i.e., by adding "["poly-"]") the discussion of Remark  4.8.1, (ii) (4 instances), (iii) (1 instance) Inter-universal Teichmuller Theory III -------------------------------------- ・Corrected a misprint ("prime strip" ---> "prime-strip", 2 instances) in  the discussion following Fig. I.2 ・Deleted a mistaken estimate of the factorial in the discussion following  Fig. I.3 ・Updated the Acknowledgements ・In Proposition 2.1, (i), added a supplementary reference to [IUTchI],  Proposition 6.7