Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 factorial(Arg1, Arg2)

 base_digits(Arg1, Arg2)

 base_conv(Arg1, Arg2, Arg3, Arg4)

 to_base_10(Arg1, Arg2, Arg3)

 to_digits(Arg1, Arg2)

 to_digits(Arg1, Arg2, Arg3)

 to_digits(Arg1, Arg2, Arg3, Arg4)

 from_digits(Arg1, Arg2)

 from_digits(Arg1, Arg2, Arg3, Arg4)

 from_digits(Arg1, Arg2, Arg3, Arg4, Arg5)

 lcm(Arg1, Arg2, Arg3)

 gcd(Arg1, Arg2, Arg3)

 first_numbers(Arg1, Arg2)

 first_numbers(Arg1, Arg2, Arg3)

 sumf(Arg1, Arg2)

 averagef(Arg1, Arg2)

 seq(Arg1, Arg2)

 arith_seq(Arg1, Arg2)

 geom_seq(Arg1, Arg2)

 increasing(Arg1)