Yeqar-d G.GAGNE yettlemid ugrud seg usdawan imawan I yellan ur-s akk d wiyaḍ ef aya ayen akken ara yemed ,ara yelemmed d ayen I fazen s waṭas yettual er win yttekin deg 3awen iwakken ad yawed er unerni utlayan n ugrud .2 1-GARDNER-CHLOROS CITE PAR ZABOOT .THESE DE DOCTORAT LA SORBONNE ,1989-1990p113 2-piaget j,par m.sabri,7edition ,1976.memoire de magistere.2003/2004 .p12 31