On the blackboard, Professor Yi had drawn with a red chalk a pattern that closely resembled a candle. The center was a standard rectangle with a thin line extending from both top and bottom, the lengths appearing quite arbitrary.
Then, the professor held his slender bamboo pointer and tapped the blackboard.
"This pattern is the fundamental element of a Line Drawing, the Line Drawing itself."
"The very top point," the professor's pointer tapping the top of the candle drawing's shadow line, tapped again: "represents the best thing that happened during the day; the very bottom point represents the worst thing that happened during the day."
As the pointer indicated, two cloud-like explanation patterns appeared beside the upper and lower shadow lines, labeling their respective meanings. Then, the pointer moved to the bottom edge of the rectangle: