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git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25146 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
[giac] various fixes, solve[x^2/x=0] should no more return 0

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@25147 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e