Metamath Proof Explorer


Definition df-xdiv

Description: Define division over extended real numbers. (Contributed by Thierry Arnoux, 17-Dec-2016)

Ref Expression
Assertion df-xdiv โŠขรท๐‘’=xโˆˆโ„*,yโˆˆโ„โˆ–0โŸผฮนzโˆˆโ„*|yโ‹…๐‘’z=x

Detailed syntax breakdown

Step Hyp Ref Expression
0 cxdiv classรท๐‘’
1 vx setvarx
2 cxr classโ„*
3 vy setvary
4 cr classโ„
5 cc0 class0
6 5 csn class0
7 4 6 cdif classโ„โˆ–0
8 vz setvarz
9 3 cv setvary
10 cxmu classโ‹…๐‘’
11 8 cv setvarz
12 9 11 10 co classyโ‹…๐‘’z
13 1 cv setvarx
14 12 13 wceq wffyโ‹…๐‘’z=x
15 14 8 2 crio classฮนzโˆˆโ„*|yโ‹…๐‘’z=x
16 1 3 2 7 15 cmpo classxโˆˆโ„*,yโˆˆโ„โˆ–0โŸผฮนzโˆˆโ„*|yโ‹…๐‘’z=x
17 0 16 wceq wffรท๐‘’=xโˆˆโ„*,yโˆˆโ„โˆ–0โŸผฮนzโˆˆโ„*|yโ‹…๐‘’z=x