Metamath Proof Explorer


Definition df-divs

Description: Define surreal division. This is not the definition used in the literature, but we use it here because it is technically easier to work with. (Contributed by Scott Fenton, 12-Mar-2025)

Ref Expression
Assertion df-divs
|- /su = ( x e. No , y e. ( No \ { 0s } ) |-> ( iota_ z e. No ( y x.s z ) = x ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cdivs
 |-  /su
1 vx
 |-  x
2 csur
 |-  No
3 vy
 |-  y
4 c0s
 |-  0s
5 4 csn
 |-  { 0s }
6 2 5 cdif
 |-  ( No \ { 0s } )
7 vz
 |-  z
8 3 cv
 |-  y
9 cmuls
 |-  x.s
10 7 cv
 |-  z
11 8 10 9 co
 |-  ( y x.s z )
12 1 cv
 |-  x
13 11 12 wceq
 |-  ( y x.s z ) = x
14 13 7 2 crio
 |-  ( iota_ z e. No ( y x.s z ) = x )
15 1 3 2 6 14 cmpo
 |-  ( x e. No , y e. ( No \ { 0s } ) |-> ( iota_ z e. No ( y x.s z ) = x ) )
16 0 15 wceq
 |-  /su = ( x e. No , y e. ( No \ { 0s } ) |-> ( iota_ z e. No ( y x.s z ) = x ) )