type _0 = Zero type _1 = Succ[_0] type _2 = Succ[_1] type _3 = Succ[_2] type _4 = Succ[_3] type _5 = Succ[_4] type _6 = Succ[_5] type _7 = Succ[_6] type _8 = Succ[_7] type _9 = Succ[_8] type _10 = Succ[_9] type _11 = Succ[_10] type _12 = Succ[_11] type _13 = Succ[_12] type _14 = Succ[_13] type _15 = Succ[_14]