# use strictly boolean operators

Use strictly boolean operators [`and`](https://hexdocs.pm/elixir/Kernel.html#and/2), [`or`](https://hexdocs.pm/elixir/Kernel.html#or/2), and [`not`](https://hexdocs.pm/elixir/Kernel.html#not/1) in this exercise instead of [`&&`](https://hexdocs.pm/elixir/Kernel.html#&&/2), [`||`](https://hexdocs.pm/elixir/Kernel.html#%%7C%%7C/2), and [`!`](https://hexdocs.pm/elixir/Kernel.html#!/1).

Strictly boolean operators differ from their non-strict counterparts in that they require the first argument to be a boolean, and they are allowed in guards.