. "s3 has_cross_section s3 if and only if : there exists some 2d plane that intersects the bearer of s3, and the impression of s3 upon that plane has shape quality s2."^^ . "Example: a spherical object has the quality of being spherical, and the spherical quality has_cross_section round."^^ . "quality"^^ . "has_cross_section"^^ . . "has_cross_section"^^ .