Is comparing Erlang to Elixir the same as comparing Perl with PHP?

I don't know perl and php but if you know either erlang or elixir it is very quick and easy to learn the other as it is mostly a syntactical difference(and mutable variables). Both use BEAM so you can easily use code & libraries from both languages

Elixir is built on top of erlang which is why you need it for Elixir to function.

PHP's syntax is inspired by Perl and thats it.

You mentioned elixir and "Erlang". You had summoned me.

In layman's terms, Ruby and Erlang had sex. And pfffft gave birth to elixir. DNA of the Syntax following the mom, and the compiler is running in dad's bosom. Both are functional.