Simplify the following text for a Grade 10 native English-speaking person.
Original: If the word `` parallel '' is defined as constant separation , the Euclid 's fifth postulate can be proved from his first four postulates . However , if the definition is taken so that parallel lines are lines that do not intersect , Euclid 's fifth postulate is independent of his first four postulates .
Simplified: This proved that Euclid 's fifth postulate was independent of the other postulates .