sentences:  A uniform 7-polytope is one whose symmetry group is transitive on vertices and whose facets are uniform 6-polytopes.Regular 7-polytopes are represented by the Schläfli symbol {p,q,r,s,t,u} with u {p,q,r,s,t} 6-polytopes facets around each 4-face.There are exactly three such convex regular 7-polytopes