Simplify the following text for a Grade 12 native English-speaking person.
Original: Lie led the Norwegian delegation to the United Nations conference in San Francisco in 1946 and was a leader in drafting the provisions of the United Nations Security Council .
Simplified: Lie led the Norwegian delegation ( group ) to the United Nations conference in San Francisco in 1946 and was a leader in drafting the rules to set up the United Nations Security Council .