A topological space has this property if and only if there exist disjoint neighborhoods around any two disjoint points (-5[1])in the space. (-5[1])Urysohn’s lemma (-5[1])gives necessary and sufficient conditions for a topological space to have this property. The Frenet-Serret (-5[1])(“freh-NAY seh-RAY”) frame contains two objects (15[1])named for this property. The left (15[2])and right (15[1])cosets of a (*) subgroup with this property are necessarily equal, so quotient groups may only (10[1])be constructed over a subgroup with this property. Groups with this property are invariant under conjugation. The final step in the Gram-Schmidt (-5[1])process is to divide all the outputted orthogonal vectors by their magnitude so that they (10[1])have this property. (10[1]-5[1])For 10 points, identify this word which describes vectors that are perpendicular to a given surface. (10[1])■END■ (0[3])