Tondemo_Yuzuru<hiraga@slis.tsukuba.ac.jp>stupidly wrote in message news:<40961E63.5090600@slis.tsukuba.ac.jp>...
> M_SHIRAISHI wrote:
> > ?????d^2{f(x,y)}?(6xy^2?4y^2)dx^2?(2x^3?4x^2?18xy?2x)dy^2 ???
> >          ???f(x,y) ?????
> 
> ?? f(x,y) ??????????


??????Yuzuru???????????? 2004????????????? 

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