The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
top: In a Hering figure, straight horizontal rules appear curved.
bottom: In Gestalt theory boxes, a gray box against a black background appears lighter than the same gray box against a white background.
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