Description: A square is nonnegative. (Contributed by NM, 14-May-1999) (Proof shortened by Andrew Salmon, 19-Nov-2011)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | lt2.1 | |- A e. RR |
|
| Assertion | msqge0i | |- 0 <_ ( A x. A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | lt2.1 | |- A e. RR |
|
| 2 | msqge0 | |- ( A e. RR -> 0 <_ ( A x. A ) ) |
|
| 3 | 1 2 | ax-mp | |- 0 <_ ( A x. A ) |