Teacher: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Teacher: Now, understand the problem? If you are still confused, see the following example:
The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Solution: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Reason: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".

Now, solve this instance: It was the first idea of the natural rate of unemployment and said that inflation rates did not affect labour market .
Student:
It also introduced the concept of the natural rate of unemployment and argued that labor market equilibrium is independent of the rate of inflation tand and so is no long run tradeoff between unemployment and inflation .