user: Given a reference text about Our Common Future, what was the purpose of the report?

assistant: The purpose of the Our Common Future report was to focus on environmental issues on the political agenda and to discuss sustainable development.

user: What are some practical applications of Burnside's lemma in combinatorics based on this passage?

assistant: * Necklace counting problem: counting rotationally distinct necklaces of various lengths where each bead can be one of the two colors. The article counts necklaces of lengths 3 and 4, and the answer is 4 and 6, respectively.
* Colorings of a cube problem: count rotationally distinct colorings of faces of a cube. The article considers a case when 3 colors are used and the answer is 57.
* 8 queens puzzle: a classical version of the problem is counting different ways to place 8 chess queens onto an 8x8 board so that no queen attacks another (the answer is 92). With Burnside's lemma application the article counts the number of different placements of queens up to rotation and reflection, arriving at 12 as the answer.

user: What ingredients are no longer used in ketchup?

assistant: Ketchup used to contain many different ingredients that created the sweet and sour flavor traditionally associated with tomato ketchup, including egg whites, mushrooms, oysters, grapes, mussels, or walnuts.