Description: Define division between real numbers. This operator saves ax-mulcom over df-div in certain situations. (Contributed by SN, 25-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-rediv | ⊢ /ℝ = ( 𝑥 ∈ ℝ , 𝑦 ∈ ( ℝ ∖ { 0 } ) ↦ ( ℩ 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | crediv | ⊢ /ℝ | |
| 1 | vx | ⊢ 𝑥 | |
| 2 | cr | ⊢ ℝ | |
| 3 | vy | ⊢ 𝑦 | |
| 4 | cc0 | ⊢ 0 | |
| 5 | 4 | csn | ⊢ { 0 } |
| 6 | 2 5 | cdif | ⊢ ( ℝ ∖ { 0 } ) |
| 7 | vz | ⊢ 𝑧 | |
| 8 | 3 | cv | ⊢ 𝑦 |
| 9 | cmul | ⊢ · | |
| 10 | 7 | cv | ⊢ 𝑧 |
| 11 | 8 10 9 | co | ⊢ ( 𝑦 · 𝑧 ) |
| 12 | 1 | cv | ⊢ 𝑥 |
| 13 | 11 12 | wceq | ⊢ ( 𝑦 · 𝑧 ) = 𝑥 |
| 14 | 13 7 2 | crio | ⊢ ( ℩ 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) |
| 15 | 1 3 2 6 14 | cmpo | ⊢ ( 𝑥 ∈ ℝ , 𝑦 ∈ ( ℝ ∖ { 0 } ) ↦ ( ℩ 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) ) |
| 16 | 0 15 | wceq | ⊢ /ℝ = ( 𝑥 ∈ ℝ , 𝑦 ∈ ( ℝ ∖ { 0 } ) ↦ ( ℩ 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) ) |