<wob_jonas> perl -eopen$i,"<",($f="wisdom/aristotle");$_=<$i>; s/, even though.*\\. / without checking. / or die; if (1) { open$o,">",$f; print$o $_ or die; } print substr$_,0;

|a+b@| = { √(a²-b²) if a²-b² ≥ 0 ; i√(a²-b²) if a²-b² < 0 }