Big Natural numbers and Big Integers as string
val bigzero: bigint
val normalize : bigint -> bigint
val bigint: int -> bigint
val fromString : string -> bigint
val toString : bigint -> string
val int : bigint -> int option
val ~~ : bigint -> bigint
val abs : bigint -> bigint
val ++ : bigint * bigint -> bigint
val succ : bigint -> bigint
val min : bigint * bigint -> bigint
val max : bigint * bigint -> bigint
val sign : bigint -> int
val sameSign : bigint * bigint -> bool
val ** : bigint * bigint -> bigint
val compare : bigint * bigint -> Bn.order
val << : bigint * bigint -> bool
val <<= : bigint * bigint -> bool
val >> : bigint * bigint -> bool
val >>= : bigint * bigint -> bool
val == : bigint * bigint -> bool
val len : bigint -> int
val lenCompare : bigint * bigint -> Bn.order
val lenLt : bigint * bigint -> bool
val lenLeq : bigint * bigint -> bool
val lenGt : bigint * bigint -> bool
val lenGeq : bigint * bigint -> bool
val lenEq : bigint * bigint -> bool
val -- : bigint * bigint -> bigint
val pred : bigint -> bigint