Description: 2 + 5 = 7. (Contributed by SN, 24-Aug-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 2p5e7 | ⊢ ( 2 + 5 ) = 7 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 2cn | ⊢ 2 ∈ ℂ | |
| 2 | 3cn | ⊢ 3 ∈ ℂ | |
| 3 | 1 2 1 | addassi | ⊢ ( ( 2 + 3 ) + 2 ) = ( 2 + ( 3 + 2 ) ) |
| 4 | 2p3e5 | ⊢ ( 2 + 3 ) = 5 | |
| 5 | 4 | oveq1i | ⊢ ( ( 2 + 3 ) + 2 ) = ( 5 + 2 ) |
| 6 | 5p2e7 | ⊢ ( 5 + 2 ) = 7 | |
| 7 | 5 6 | eqtri | ⊢ ( ( 2 + 3 ) + 2 ) = 7 |
| 8 | 3p2e5 | ⊢ ( 3 + 2 ) = 5 | |
| 9 | 8 | oveq2i | ⊢ ( 2 + ( 3 + 2 ) ) = ( 2 + 5 ) |
| 10 | 3 7 9 | 3eqtr3ri | ⊢ ( 2 + 5 ) = 7 |