Description: The absolute value of a number is zero iff the number is zero. Proposition 10-3.7(c) of Gleason p. 133. (Contributed by NM, 28-Jul-1999)
Ref | Expression | ||
---|---|---|---|
Hypothesis | absvalsqi.1 | |- A e. CC |
|
Assertion | abs00i | |- ( ( abs ` A ) = 0 <-> A = 0 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | absvalsqi.1 | |- A e. CC |
|
2 | abs00 | |- ( A e. CC -> ( ( abs ` A ) = 0 <-> A = 0 ) ) |
|
3 | 1 2 | ax-mp | |- ( ( abs ` A ) = 0 <-> A = 0 ) |