Metamath Proof Explorer


Definition df-div

Description: Define division. Theorem divmuli relates it to multiplication, and divcli and redivcli prove its closure laws. (Contributed by NM, 2-Feb-1995) Use divval instead. (Revised by Mario Carneiro, 1-Apr-2014) (New usage is discouraged.)

Ref Expression
Assertion df-div
|- / = ( x e. CC , y e. ( CC \ { 0 } ) |-> ( iota_ z e. CC ( y x. z ) = x ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cdiv
 |-  /
1 vx
 |-  x
2 cc
 |-  CC
3 vy
 |-  y
4 cc0
 |-  0
5 4 csn
 |-  { 0 }
6 2 5 cdif
 |-  ( CC \ { 0 } )
7 vz
 |-  z
8 3 cv
 |-  y
9 cmul
 |-  x.
10 7 cv
 |-  z
11 8 10 9 co
 |-  ( y x. z )
12 1 cv
 |-  x
13 11 12 wceq
 |-  ( y x. z ) = x
14 13 7 2 crio
 |-  ( iota_ z e. CC ( y x. z ) = x )
15 1 3 2 6 14 cmpo
 |-  ( x e. CC , y e. ( CC \ { 0 } ) |-> ( iota_ z e. CC ( y x. z ) = x ) )
16 0 15 wceq
 |-  / = ( x e. CC , y e. ( CC \ { 0 } ) |-> ( iota_ z e. CC ( y x. z ) = x ) )