This proof proves the theorem
x,y:. |x| = |y| x = y

The following definitions are used in this proof:

absval (absolute value)
|i| == if 0 z i then i else -i fi
pm_equal (equals plus or minus)
i = j == i = j i = -j
Please do the following and record your answers:
  • Translate this proof into English.
  • Was there any part of this proof that you found difficult to translate? If so, why?
  • Do you think that this theorem was proved in a natural or intuitive manner or not? If so, why?

Link to Proof Two


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Intro to the Study | Introduction to Nuprl | How to Read Nuprl Proofs | Tactic Definitions | Starting the Study | Exiting the Study

In case of questions contact:

Amanda Holland-Minkley
E-mail: hollandm@cs.cornell.edu
Phone: 255-1181
Office: Upson 5141