Puzzle #87: 2,0,1,5

Using each of the digits in 2015 once along with addition, subtraction, multiplication, division, factorial (3! = 1 × 2 × 3 = 6, and 0! = 1), unary negation (as in -2 + 5 = 3), and brackets, as you choose, devise expressions. (For example, 2 + 0 – 1 + 5! equals 121, and (2 + 0) × (1 + 5) equals 12.)

Do this for each of the whole numbers from 0 to 10. For more of a challenge, have the digits appear in the order 2, 0, 1, and 5.

Submit your answer to Gene Wirchenko <genew@telus.net>. Your answer should be in the form of a proof. That means to show how your answer must be correct. The deadline is Wednesday, February 4, 2015 at noon Pacific Time. I will post the answer shortly after.