minimal entity page
xy -plane
Drawing a horizontal line anywhere in the [xy -plane|xy -plane] results in a graph that cannot intersect the line more than once, as per the horizontal line test.
Causes
The <a href='/en/entity/horizontal-line'>horizontal line test</a> ensures that a horizontal line drawn anywhere in the xy -plane cannot intersect the graph more than once.
Effects
Drawing a horizontal line anywhere in the xy -plane results in a graph that cannot intersect the line more than once, as per the horizontal line test.
Comparison
xy -plane The <a href='/en/entity/horizontal-line'>horizontal line test</a> applies to the xy -plane by ensuring that any horizontal line drawn cannot intersect the graph more than once.