Description: The absolute value of a real number is either that number or its negative. (Contributed by NM, 30-Sep-1999)
Ref | Expression | ||
---|---|---|---|
Hypothesis | sqrtthi.1 | |
|
Assertion | absori | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sqrtthi.1 | |
|
2 | absor | |
|
3 | 1 2 | ax-mp | |