HAL Id: inria-00074531
https://hal.inria.fr/inria-00074531
Submitted on 24 May 2006
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About the rational map
Bernard Mourrain
To cite this version:
ISSN 0249-6399
a p p o r t
d e r e c h e r c h e
1 9 9 4
INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET AUTOMATIQUE
About the rational map
associated to a parallel robot
Bernard Mourrain
N˚ 2141
Novembre 93
PROGRAMME 2
Calcul symbolique,
programmation
et ge´nie logiciel
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