question: @ Override public final boolean equals ( Object p_ob ) { if ( ! ( p_ob instanceof PlaPointRational ) ) return false ; PlaPointRational other = ( PlaPointRational ) p_ob ; BigInteger det = MathAux . determinant ( rp_x , other . rp_x , rp_z , other . rp_z ) ; if ( det . signum ( ) != 0 ) return false ; det = MathAux . determinant ( rp_y , other . rp_y , rp_z , other . rp_z ) ; return ( det . signum ( ) == 0 ) ; }
target:  returns true, if this RationalPoint is equal to p_ob