One line custom validation

In a Proc I would like to validate that the provided statement returns true.

I tried the following:

validate :home, Proc.new { |c| c.home.kitchen.present? }

It does not work. It does not show validations errors when no kitchen is present.

Do I have to write it like this:

validate :home_kitchen_must_be_present

def home_kitchen_must_be_present
   ....

Or is there an available syntax to write it in one line? Thanks