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Description: A number is zero iff its square is zero (where square is represented using multiplication). (Contributed by NM, 28-Jul-1999)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | msq0i.1 | ⊢ 𝐴 ∈ ℂ | |
| Assertion | msq0i | ⊢ ( ( 𝐴 · 𝐴 ) = 0 ↔ 𝐴 = 0 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | msq0i.1 | ⊢ 𝐴 ∈ ℂ | |
| 2 | 1 1 | mul0ori | ⊢ ( ( 𝐴 · 𝐴 ) = 0 ↔ ( 𝐴 = 0 ∨ 𝐴 = 0 ) ) |
| 3 | oridm | ⊢ ( ( 𝐴 = 0 ∨ 𝐴 = 0 ) ↔ 𝐴 = 0 ) | |
| 4 | 2 3 | bitri | ⊢ ( ( 𝐴 · 𝐴 ) = 0 ↔ 𝐴 = 0 ) |