open cover

American  

noun

Mathematics.

1. a cover of a set consisting entirely of open sets.

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Example Sentences

This will be equally good the next day, if kept in a cool place, with an open cover, which prevents all danger of souring.

From Clayton's Quaker Cook-Book Being a Practical Treatise on the Culinary Art Adapted to the Tastes and Wants of all Classes by Clayton, H. J.

These pretty and useful baskets had on each side a bunch of flowers peeping out through the open cover, and on the gilt handle was tied a ribbon corresponding in color to the flowers.

From Manners and Social Usages by Sherwood, Mrs. John M. E. W.

Place the book flat upon the table, the front cover open, take book of similar thickness and place under open cover.

From Mending and Repair of Books by Brown, Margaret Wright

After well hoeing and weeding in spring, until blossom-buds appear, just before the blossoms open, cover the bed thoroughly with spent tanbark, sawdust, or fine straw.

From Soil Culture by Walden, J. H.

By keeping just in their rear we might be able to urge them gently along until they should enter more open cover.

From The Land of Footprints by White, Stewart Edward