## Introduction

Nemo provides a unified interface to handle factorizations using the Fact objects. These can only be constructed using the factor function for the respective ring elements. This is best illustrated by an example.

julia> fac = factor(ZZ(-6000361807272228723606))
-1 * 2 * 229^3 * 43669^3 * 3

julia> unit(fac)
-1

julia> -6000361807272228723606 == unit(fac) * prod([ p^e for (p, e) in fac])
true

julia> for (p, e) in fac; println("$p$e"); end
2 1
229 3
43669 3
3 1

julia> 229 in fac
true

julia> fac[229]
3


## Basic functionality

Objects of type Fac are iterable, that is, if a is an object of type Fac, then for (p, e) in a will iterate through all pairs (p, e), where p is a factor and e the corresponding exponent.

in{T}(a::T, ::Fac{T})
getindex{T}(::Fac{T}, T)
length(::Fac)
unit(::Fac)