Definitions for "Epigraph"
Any inscription set upon a building; especially, one which has to do with the building itself, its founding or dedication.
A citation from some author, or a sentence framed for the purpose, placed at the beginning of a work or of its separate divisions; a motto.
a quotation, sometimes at the beginning of a poem or novel, that sets forth a theme.
Keywords:  abbr, graph, region, above
(abbr. epi{f,X}). {(x, z): x in X, z = f(x)} = region on or above the graph of f.