Description: Define the set of closed intervals of extended reals. (Contributed by NM, 24-Dec-2006)
Ref | Expression | ||
---|---|---|---|
Assertion | df-icc | |- [,] = ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z <_ y ) } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cicc | |- [,] |
|
1 | vx | |- x |
|
2 | cxr | |- RR* |
|
3 | vy | |- y |
|
4 | vz | |- z |
|
5 | 1 | cv | |- x |
6 | cle | |- <_ |
|
7 | 4 | cv | |- z |
8 | 5 7 6 | wbr | |- x <_ z |
9 | 3 | cv | |- y |
10 | 7 9 6 | wbr | |- z <_ y |
11 | 8 10 | wa | |- ( x <_ z /\ z <_ y ) |
12 | 11 4 2 | crab | |- { z e. RR* | ( x <_ z /\ z <_ y ) } |
13 | 1 3 2 2 12 | cmpo | |- ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z <_ y ) } ) |
14 | 0 13 | wceq | |- [,] = ( x e. RR* , y e. RR* |-> { z e. RR* | ( x <_ z /\ z <_ y ) } ) |