Submission: 2007, Nov 16, revised: 2008, Nov 16
Following Soulé's ideas we give a presentation of the abstract group G(k[t] for any semisimple simply connected group absolutely almost k-simple group G. As an applications, we give a description of G(k[t]) in terms of direct limits, and show that the Whitehead group and the na´ve group of connected components of G coincide.
2000 Mathematics Subject Classification: 20G10, 22
Keywords and Phrases: Bruhat-Tits buildings, arithmetic groups, simplicial fundamental domain.
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