HomeRelated theorems
Unicode version
| Home |
Metamath Proof Explorer |
< Previous
Next >
Related theorems Unicode version |
Description: Define minus infinity as
the power set of plus infinity. Note that the
definition is arbitrary, requiring only that  be a set not in
 and different
from  (see mnfnre 5480 and pnfnemnf 5519). |
| Ref | Expression |
|---|---|
| df-mnf |
   |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cmnf 5467 |
. 2
 | |
| 2 | cpnf 5466 |
. . 3
| |
| 3 | 2 | cpw 2398 |
. 2
|
| 4 | 1, 3 | wceq 955 |
1
 |
| Colors of variables: wff set class |
| This definition is referenced by: mnfxr 5477 mnfnre 5480 pnfnemnf 5519 |