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Description: The absolute value of 0. (Contributed by NM, 26-Mar-2005) (Revised by Mario Carneiro, 29-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | abs0 | ⊢ ( abs ‘ 0 ) = 0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0cn | ⊢ 0 ∈ ℂ | |
| 2 | absval | ⊢ ( 0 ∈ ℂ → ( abs ‘ 0 ) = ( √ ‘ ( 0 · ( ∗ ‘ 0 ) ) ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ( abs ‘ 0 ) = ( √ ‘ ( 0 · ( ∗ ‘ 0 ) ) ) |
| 4 | 1 | cjcli | ⊢ ( ∗ ‘ 0 ) ∈ ℂ |
| 5 | 4 | mul02i | ⊢ ( 0 · ( ∗ ‘ 0 ) ) = 0 |
| 6 | 5 | fveq2i | ⊢ ( √ ‘ ( 0 · ( ∗ ‘ 0 ) ) ) = ( √ ‘ 0 ) |
| 7 | sqrt0 | ⊢ ( √ ‘ 0 ) = 0 | |
| 8 | 3 6 7 | 3eqtri | ⊢ ( abs ‘ 0 ) = 0 |