Letters that make patent of invention
a, o, e, f, n, p, t, i, v are letters that make 'patent of invention'
Words within patent of invention
pat, PA, pate, ti, te, NT, at, Pa, en, invent, patent, on, ten, in, invention, vent, IN, NV, Io, ion, tent, Aten, Ate, pa, At, In, Te, Ti are words within 'patent of invention'