Here is another concrete example, illustrated by a Venn diagram. These overlays are similar to mathematical Venn diagram overlays. The child element is within the parent element, such as in a Venn diagram. His great-grandson was the logician and philosopher John Venn, famed for the Venn diagram. Relations of various RIF dialects are shown in the following Venn diagram. Less-related visual signs include the Gankyil and the Venn diagram on three sets. The Venn diagram (below) illustrates the above clauses graphically. A Venn diagram is a representation of a Boolean operation using shaded overlapping regions. To visualize "g", imagine a Venn diagram with four circles overlapping. A Venn diagram consists of multiple overlapping closed curves, usually circles, each representing a set.