Metamath Proof Explorer


Definition df-rediv

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 / = ( 𝑥 ∈ ℝ , 𝑦 ∈ ( ℝ ∖ { 0 } ) ↦ ( 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 crediv /
1 vx 𝑥
2 cr
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 / = ( 𝑥 ∈ ℝ , 𝑦 ∈ ( ℝ ∖ { 0 } ) ↦ ( 𝑧 ∈ ℝ ( 𝑦 · 𝑧 ) = 𝑥 ) )